Hioki 3532-50 LCR Repair (One major problem solved, SM still wanted) - Page 1
Forum section: electronics / repair

author: Martin72
author_rank: Super Contributor
timestamp: December 06, 2022, 06:12:17 pm
content: Hi at all,Today a defective Hioki 3522-50 LCR meter arrived, bought it from ebay - Having eventually a 5 Mhz LCR sounds so sweet in my ears, I can´t withstand...Optically it´s "so la la", technically:Switched it on and indeed, nothing happens except a relais clicking is hearable from somewhere.Examining the inside, one of the pcbs got a Batteryclip, the Battery is leaked out.Voltages I didn´t check so far.Question in the round:Are there schematics or much better a service manual avaible ?Martin

author: Martin72
author_rank: Super Contributor
timestamp: December 06, 2022, 07:42:50 pm
content: Pics...First shows the pcb with the "rotten" battery.In the upper left corner, to my surprise there´s an inverter for the backlight of the LCD - Interesting.I´ve wrote to hioki but hopes are low getting a suitable answer concerning any docs...But you can´t know it when you´re not trying it.Otherwise the usual steps for investigation will following on the next weekend.I´ll report..

author: coromonadalix
author_rank: Super Contributor
timestamp: December 06, 2022, 07:47:32 pm
content: Usuals checks like the psu voltagesyou should check under the corroded battery holder, if some traces have been damaged ??And sadly, i doubt Hioki will answer your requests, ask them under an non disclosure agreement (NDA) ??

author: Martin72
author_rank: Super Contributor
timestamp: December 06, 2022, 07:56:01 pm
content: QuoteOf course, also what the layers towards the battery concerns.Having a schematic makes it easier, but it´s not impossible without.Tomorrow I desolder the batteryclip at work, I think I´ve found a one which will fit into.Sometimes without a battery nothing will start, maybe I got luck.QuoteYes, hopes are low.But I´ll try everything to fix it - Used ones(5Mhz versions like mine) are not avaible under 2000 bucks.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 07, 2022, 01:30:38 am
content: Not sure if they keep some configurations with the cell battery, and if the battery dies, you loose somethingOr have an memory corruption ?? you best luck would be to find this control boardeasier said than donegood luck

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 07, 2022, 10:13:49 am
content: Did you write to Hioki Japan directly?If you have no luck, I can contact them in Japanese. Sometimes that is more effective.

author: Martin72
author_rank: Super Contributor
timestamp: December 07, 2022, 06:47:45 pm
content: I received an automatic answer from hioki.jp, so I think it´s the japan site.QuoteTell you then.

author: Martin72
author_rank: Super Contributor
timestamp: December 09, 2022, 08:49:04 pm
content: No response until this afternoon from hioki..Maybe it smells "fishy" for them because I´ve filled out the contact formular in such manner they want you to do, with your company adress, department, email...Maybe I´ve should wrote, it´s only for private usage....Today the "proforma" batteryclip arrived from amazon, a capsuled one with leads - for first try it´s OK.PCB itself didn´t got any further damages through the leakage, after cleaning the solder side it looks like new.Tomorrow soldering the clip, new battery, then next attempt including measuring of the aux. voltages.BTW...You´ll never get one piece from amazon concerning articles like this - Anyone interested in 29 batteryclips with leads ?!

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 11:53:43 am
content: NEVER underestimate the meaning of a backup battery...It runs!After assembling/soldering and turning on, nothing happens...I start measuring voltages, but after a while a system beep comes up.Since then, turning off/on, always powered on, yeah !But still I want to have the SM or at least a part list, because light won´t go on and the touchpanel won´t work proper anymore, because there´s air or moisture in a kind of moveable bubble inside.Also the Display got a "dead" line, but hey....it works basically, really great.To be continued...

author: coromonadalix
author_rank: Super Contributor
timestamp: December 10, 2022, 12:30:24 pm
content: you have a dead backlight it seems ??For the touchscreen, never seen this kind with so many pins, for the bubble, it would need to slightly try to create a vent between the layers and gently push the bubble out, unless it re create it ??The problem is: be careful, you have an flex trace going all the way around the touch, you must be very carefulAnd i dont see the lcd number markings ?? just an sed1335 lcd controller ic, on the main board, it means the lcd as no main (brain)control logic, it has col and rows drivers ....You have the cfl driver on the main board too

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 12:35:02 pm
content: QuoteActually I think so, but you got a menu where you could turn it on or off - when the panel would recognize my touch...Try it out again, report.Also pics from the display will follow...

author: coromonadalix
author_rank: Super Contributor
timestamp: December 10, 2022, 12:36:39 pm
content: you where faster than me writting my previous thread loll i was editing some infosFor the lcd it could be some zebra strips with bad contactsbe sure you have nothing who touch some drivers ic's on the lcd ....This lcd should be easily dismantable, with rotated frame pins, remove solder blobs who ground the black frame ??

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 12:48:37 pm
content: Thank you for the advicesI´m into test&repair since 20yrs but you´ll never know everything.Interesting thing:After unpowered for say a half hour, I´ve powered on again....Nothing.Leave it to on...After say a minute or little more, system boots up.Then when you turn off and on again, system boots up immediately...Whats going on..Need a schematic...Nevertheless, pics from the display will come soon.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 10, 2022, 01:04:16 pm
content: Maybe over time not sure if you have some ram corruption or sluggynessI had equipement with some ram failure, it was booting very slow, but was perfectly functionning, changed the part, and bam it was speedy ??Not sure of this one, something could affect it's boot time, but still seems to function normally after a whileAnd the usual suspects are the supply lines, noises, spikes, bad capacitors ...I would say to get an idea: check every part number on the cpu board, try to get their datasheet, and try to figure out some basic functions like watchdog, reset circuitry etc ...And i doubt Hioki will give an schematic, you may (and i hope not) never get an service manual ??

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 01:17:46 pm
content: Yepp, will examine also the power lines which are going to the controller board with scope.Maybe today, maybe tomorrow.Here a dedicated pic of the LCD panel´s backside.It´s from Powertip, model PG320240C

author: coromonadalix
author_rank: Super Contributor
timestamp: December 10, 2022, 02:00:11 pm
content: thks an 320 by 240 pixels glcd wow some high prices there, cheaper prices on EbayNot being rude, you have an expensive puppy to repair lollFor the touch screen, i hope you will be able to remove the bubble, this one i'm not even sure you could find a substitute or even an original one ??With so many connector lines, i would say it's a capacitive one, But some old resistive one had many connectionsTo be sure, take a pen eraser and try to do functions, resistive will work okay, capacitive not.Once again, it's to find every part datasheet to be sure,Lots of work ahead ??

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 02:05:33 pm
content: Absolute but I´m totally convinced about that it will be worth it.

author: mawyatt
author_rank: Super Contributor
timestamp: December 10, 2022, 02:25:56 pm
content: Hioki provides very high quality instruments, maybe some of the best available from Japan, and they are expensive!!Seems you've found a "Jewel in the Rough", hope you can return it to a useful life and be rewarded for your effortsBest,

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 05:42:37 pm
content: I got good hopes to fix it, but I also want to polish it in optically way after this.I´ve payed 290€ for it, this is nothing for a 5Mhz Bridge (is it a bridge....).It would be fantastic to get the SM or spare parts like the touchpanel or even the front.The front is nearly yellow....

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 06:41:17 pm
content: Identified the chips on the controllerboard(and named them in the pic)Actual mostly interesting is the battery control chip upper left.Will measure it tomorrow, it controls resetting....Martin

author: coromonadalix
author_rank: Super Contributor
timestamp: December 10, 2022, 08:36:33 pm
content: Check ic108 a 3 pin sot, near one of the ram, try to find what it isthe SED lcd controller has a ram chip for itselfseem pretty simple logic loll lots are hidden in the fpga ....Unlees the flash chip has began to deteriorate, but you say it eventually workI would still suspect the ram ic's ??With the datasheets, you are able to measure many ic's vcc pins voltage(s)Suprised to see somekind of a clock generator instead of a crystal ??For the yellowish color, there was some talk here about whitening plastic / restoration etc ...

author: Martin72
author_rank: Super Contributor
timestamp: December 10, 2022, 10:46:47 pm
content: Hi,Tomorrow I´ll turn my scope on and doing some measures.First the reset signal from the battery controller chip, then looking further.It must be something which last a while, maybe a voltage to come up on the right level.When it´s something with the RAM...As long as they are avaible I don´t care.At work I got access to a rework station so this would be a minor problem.QuoteThere´s a second oscillator on the main pcb.QuoteGood to read, post tomorrow a pic of the front panel.

author: Martin72
author_rank: Super Contributor
timestamp: December 11, 2022, 11:08:07 am
content: I´m coming closer to to the solution...Not done scope measuring yet, but this will be the next, because:The 5V voltage (I guess it is) from the supply starts with appx 4.2V (meter reading) and increase slowly, at appx 4.4V the system boots up because the battery control chip release the reset signal then.This is not normal...Next is watching the 5V signal how its look like - Unfortunately at later afternoon, part of the sunday is reserved for family.Stay tuned.Martin

author: Martin72
author_rank: Super Contributor
timestamp: December 11, 2022, 11:59:29 am
content: Short snip before I´m off:Got it..It´s the 5V supply..

author: Martin72
author_rank: Super Contributor
timestamp: December 11, 2022, 05:06:38 pm
content: Hi,A Multimeter is never enough for failure analyzis...This I´ve learned over 20yrs ago in a "painful" way and it´s still valid.Looking at the 5V for the Controlboard with scope, first setting the timebase to 10s because I wanted to see the signal rising.But there´s no rising, there´s a huge noise on the dc-signal, reduce timebase to µs, aha...Something is heavy oscillating and the signal remains even when you disconnect the plug from the controlboard, so it´s definetly on the supply board.The board itself is "simple" as it can gets, several aux voltages from the transformer goes through rectifiers and then stabilizing with classical 78/79xx types, plus one 317.And where every other voltage is clean, the 5V for the controller is oscillating.So the 5V regulator must be replaced.I got several ones here, but not in fully isolated housings.Maybe for testing I´ll take one.So or so, I think this was it...If I´m right, next step will follow, what to do with the touch panel and (perhaps) with the backlight.Martin(edit why are the pics "shuffled"...it´s not my order I´ve placed them)

author: Martin72
author_rank: Super Contributor
timestamp: December 13, 2022, 06:34:05 pm
content: Today the regulator arrived and I must correct me, there are no ordinary 78/79XX types on the board, they´re LDO types..The original one is hard to get so I took one from TI, but with non-isolated case.Therefore I´ve ordered electric isolating heatpads and thermal paste additionally, everything from amazon, including the LDO.I guess on friday I can exchange the both and then....we will see.Martin

author: coromonadalix
author_rank: Super Contributor
timestamp: December 13, 2022, 10:27:42 pm
content: Normally the metallic will be fine, and if you have over minimum 2 volts between in and out it should regulate fine ....That's why an LDO is preferredNice scope BTW

author: Martin72
author_rank: Super Contributor
timestamp: December 13, 2022, 10:38:53 pm
content: QuoteI know and this is something it nerves me a little bit because I didn´t pay attention on the inputvoltage of the original LDO.This I´ll do before exchanging it on the weekend.But I must say, this is already done in my head, I expect this problem is solved then and my thoughts are with the touchpanel, which I couldn´t find anywhere in the www....QuoteAbsolutely, actually I´m very confident with it.

author: coromonadalix
author_rank: Super Contributor
timestamp: December 14, 2022, 12:57:21 am
content: Unless you have a slow rising voltage before the regulator ?? like an defective rectifier bridge, cold solder ??Maybe take some measurements with everything connected normally?? even if it could or will do the boot problem ??

author: Martin72
author_rank: Super Contributor
timestamp: December 14, 2022, 09:44:55 pm
content: Hi,Indeed I must make some more measurements:Today I wanted to desolder the original LDO at work because of the double-layer pcb ( more powerful solder station there).Before I´ve powered it on with a external dc voltage of about 10V - And measured proper 5V at the output of the LDO and with less ripple noise.This means it must be something wrong with the rectifier bridge, the cap or the ac source from the transformer.Will look at it on friday.

author: Martin72
author_rank: Super Contributor
timestamp: December 16, 2022, 11:48:28 pm
content: The new LDO ordered from amazon got a different pinout...Before I´ve checked the AC-Voltages, all seems to be OK.Rectified, the DC inputvoltage for the LDO is about 8.4V - that would be enough to use an ordinary 7805 for testing only.More and more I think a cap was damaged, because without the regulator the DC voltage is clear without remarkable ripple noise.Will find it out on saturday..Still no response from hioki, I guess I won´t get any answer from them.

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 17, 2022, 05:19:57 am
content: I'll send off an email in Japanese this weekend.Maybe if they can read the email they won't ignore it....

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 17, 2022, 05:59:38 am
content: I made a login for the Japanese website and scoured both Japanese and USA website for documents.Doesn't look like there is a service manual available for download, but I'll still send that email and see what happens.Below is a Google Drive link to what I found so far, you'll need to use google translate for some of them. But there are English and Japanese versions of most of the documents. (Installing google translate on your phone to use the camera to read the Japanese can get you by)https://drive.google.com/drive/folders/1b338VuEMozyoGD3ITF6zMTojXjcmHjgN?usp=sharingAs a bonus I found LabView drivers and a sample application software thingo for pulling data via serial to generate csv files etc.

author: Martin72
author_rank: Super Contributor
timestamp: December 17, 2022, 05:20:43 pm
content: Success !With the ordinary 7805 regulator I get a clean 5V for the controllerboard, result: Immediately booting up after powering on...Got slight problems of a mechanical nature because of the non-isolated package but this is nothing against the fact I´ve found the failure...So one mature failure is solved, things to polish:- Battery Clip, the old one can be used after cleaning, will follow.- Original regulator (LDO) will be searched, in this time:- Correct mounting the 7805 onto the backside.Next mature failure is waiting, the touchpanel....It´s getting more and more worse, nearly no response...must have it new, but where to buy..Need the SM or at least a list of the spareparts part-numbers, in the hope I could buy it.And then the very yellow frontpanel, but this is cosmetic, not top of the list.To be continued with a summary todo list..

author: coromonadalix
author_rank: Super Contributor
timestamp: December 17, 2022, 08:49:14 pm
content: There is some receipe on the web to remove yellowish color from plasticsPeroxyde or bleach .....https://cleaning.lovetoknow.com/cleaning-tips/how-whiten-yellowed-plastic-simple-safe-methods

author: Martin72
author_rank: Super Contributor
timestamp: December 17, 2022, 08:59:48 pm
content: Interesting methods there, but are there no concerns about the labels on the panel ?Not that I have a clean white front after this - And nothing else anymore...

author: Martin72
author_rank: Super Contributor
timestamp: December 17, 2022, 11:00:04 pm
content: The frontpanel...I would love to buy a new one...but let´s see what´s possible with this one.

author: Martin72
author_rank: Super Contributor
timestamp: December 18, 2022, 10:20:35 am
content: QuoteFind one in ebay:new chinese panelNearly 200 bucks incl. shipping..

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 18, 2022, 11:12:07 am
content: I've found the retrobrite thing (I usually use just plain hydrogen peroxide) works well, it has done some good work on yellowed HP buttons with no effect on the clear plastics or on the labelling.Too bad the touch screen isn't a standard 4-wire thing. Maybe you could make a circuit to convert a cheaper touch overlay?

author: Martin72
author_rank: Super Contributor
timestamp: December 18, 2022, 11:50:51 am
content: Hi,Must think about it (and find the right size, the right matrix).Otherwise I´ve spend appx 300 for the defective unit, when adding 200 bucks or a little more, I´m still way under the price of a used one with 5Mhz...But let´s see and let´s hope You got success what the SM concerns.Martin

author: coromonadalix
author_rank: Super Contributor
timestamp: December 18, 2022, 03:10:51 pm
content: I would buy the original right awayFor the 4 or 5 wires or even the 8 wires touchscreens you have an interfcace ic, it depend how the matrix in it has been designed

author: Martin72
author_rank: Super Contributor
timestamp: December 18, 2022, 10:50:04 pm
content: I´ve asked the ebay-seller for more pictures from the panel - on the only one the connections are looking different to mine and I don´t want to get a bad surprise..At the same time I´ve started a request by an official german hioki seller what spareparts concerns.

author: Martin72
author_rank: Super Contributor
timestamp: December 22, 2022, 09:52:33 pm
content: The seller told me it is the right one...Hmm, but will wait a little bit until an answer fron the hioki seller arrived.Meanwhile I´ve bought two different cleaner against yellowing - both didn´t work for several reasons, now uv-lights and hydrogen peroxide are ordered..Maybe I should ask the official hioki seller for a service manual..Worth a try.

author: Martin72
author_rank: Super Contributor
timestamp: December 27, 2022, 11:16:23 pm
content: Nothing new...No response from hioki, no reaction so far from the official distributor.Time for the rebright thing...Now I got everything together, will start tomorrow.When succesful, a extra thread about will follow.

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 28, 2022, 06:10:46 am
content: News back from Hioki Japan. Basically a big nope.Essentially, they have completely dropped any and all support and have no intention of releasing any service information at all.It's a bit polarised with this sort of thing in Japan, I've had some companies (Yokogawa, Advantest etc) go to great lengths to get me obsolete info, One guy at Advantest actually took their one remaining manual for a nixie frequency counter home to scan on his own scanner!Other times, like this time, you just get stonewalled with a "Go buy our new model"......All I can suggest is to try contacting other regional offices, or try to find a friendly third-party service agent that will sell or make a copy of the service manual.I'll keep an eye out here too, maybe a manualmightpop up one day on yahoo auctions etc. I added a few more documents to the google drive link, mostly just sales stuff..

author: Martin72
author_rank: Super Contributor
timestamp: December 28, 2022, 11:04:36 pm
content: Patiently waiting...

author: Martin72
author_rank: Super Contributor
timestamp: January 01, 2023, 04:35:42 pm
content: After 4 days, it doesn't look perfect, but very much better than before.Great thing.

author: DavidKo
author_rank: Frequent Contributor
timestamp: January 03, 2023, 05:56:58 pm
content: Quote from: TERRA Operative on December 28, 2022, 06:10:46 amSame experience here. I have asked for SM for Hioki 7020 and got the same reply (it was quick, but useless). There is even no replacement device as far as I know and they had dropped the support (I have not asked, but I expect that they will even not calibrate it).

author: mawyatt
author_rank: Super Contributor
timestamp: January 03, 2023, 06:24:17 pm
content: Quote from: DavidKo on January 03, 2023, 05:56:58 pmThe IM3536 might be the replacement LCR Meter, it covers from 4Hz to 8MHz.Best,

author: DavidKo
author_rank: Frequent Contributor
timestamp: January 04, 2023, 06:29:20 am
content: Quote from: mawyatt on January 03, 2023, 06:24:17 pmI meant, that they do not give you the support even if the device (in my case Hioki 7020 AC/DC signal source) do not have a Hioki replacement.

author: TERRA Operative
author_rank: Super Contributor
timestamp: January 04, 2023, 10:25:14 am
content: I found a Japanese user manual for sale here on Yahoo Auctions, but it's not the service manual... It's the same one in my google drive link above.At least it shows that manuals are being sold, so I'll keep an eye out, we might find a service manual one day...........

author: Martin72
author_rank: Super Contributor
timestamp: January 05, 2023, 10:16:11 pm
content: No response from the hioki distributor so far, next week I´ll order the touchpanel from the (far east) ebay-seller.The 5V LDO is on it´s way and I think I exchange the bnc sockets too, as they´re a little bit "rusty" looking.Finally clean the contacts of the display and then....Test if the display light is ok.(you must turn it on/off in the menu, the menu I can use when the new touchpanel is assembled)That all could last some weeks...But it will be surely worth it.

author: Martin72
author_rank: Super Contributor
timestamp: January 14, 2023, 12:00:29 am
content: QuoteNo good news from them...Production ended in 2015, service support ended in 2021.This means that since that date there is nothing more for it, no spare parts and no documents like the service manual.That, in turn, was only available for authorized service workshops.Fortunately, the device does not have an electrical defect in the sense that it requires the manual.But maybe I'll be lucky someday and get it after all.Now I want to order the panel from the Ebay seller, but he is on "vacation" until February.

author: TERRA Operative
author_rank: Super Contributor
timestamp: January 14, 2023, 01:36:36 am
content: Might have to get friendly with a tech at a service center or two...

author: mawyatt
author_rank: Super Contributor
timestamp: January 14, 2023, 02:30:58 am
content: Are you sure you want to change the BNC connectors? Would think this might have an effect on the calibration, and without a cal manual, and the necessary cal standards, might not be a good idea!! Sure you may not know the cal state of the instrument as is, but changing the connectors seems it will just increase the uncertainty, altho look nicer.After you get the LDO and new front panel installed, maybe just clean the connectors as best you can for starters. BTW the original panel after you cleaned/processed it doesn't seem too bad IMO!!Best,

author: Martin72
author_rank: Super Contributor
timestamp: February 24, 2023, 05:43:59 pm
content: Tadaa....Arrived today:

author: Finity
author_rank: Contributor
timestamp: June 07, 2023, 11:15:50 am
content: Any updates on this project? Have the lesser 3522-50, and the screen, while still functional, has a few areas that take pressing twice before responding. Also, is the new screen less yellow than the aged screens for better contrast? Would consider upgrading if so. Nice project!

author: Martin72
author_rank: Super Contributor
timestamp: June 11, 2023, 04:11:40 pm
content: Hi !It's a shame but I didn't reassemble the unit so far...Will do it in the next weeks..

author: Martin72
author_rank: Super Contributor
timestamp: July 09, 2023, 09:13:09 pm
content: In the next days...

author: Martin72
author_rank: Super Contributor
timestamp: July 13, 2023, 08:14:09 pm
content: Hi,Today I assembled the new touchpanel.After some "modifications" it works fine.But...I´m afraid I need a new display.The Backlight is dead, it have some blank stripes and after a while, it "fades" off.Well...There two choices.New and Replacement:https://www.elecok.com/de/pg320240c-lcd-panel-replacement.html?origin=recentOr "original" (but new??):https://www.elecok.com/de/pg320240c-lcd-panel-original.html?origin=recentA decision of appx 160€ difference..

author: Martin72
author_rank: Super Contributor
timestamp: July 13, 2023, 10:25:23 pm
content: A service manual would be sooo helpful....When I had completely disassembled the front panel, I had unfortunately not taken any pictures of it and am currently puzzling over how what belongs back together.This complicates things a bit.I can't understand it, the support is completely stopped, there are no spare parts anymore, absolutely zero, the corresponding service partners can't do any repairs anymore - But the documents remain under lock and key...Should everyone throw away his once expensive device when it is broken ?!Anyway, it will go on, just slower without the service manual.

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 13, 2023, 11:21:49 pm
content: If it's a bad backlight, that's at least repairable. Maybe some LED's or a CCFL tube?If the problem is in the actual pixels, maybe you can open up the LCD assembly and clean the zebra strips if they are used?

author: Martin72
author_rank: Super Contributor
timestamp: July 13, 2023, 11:39:30 pm
content: Hi!QuoteThis powertip pg320240C display got a tiny CCFL tube, onboard of the hioki there´s an inverter for it.If I would buy the display substitute, this will come with a LED backlight.No greater problem, I would deactivate the inverter circuit and take the on/off signal for the LED backlight instead.The blank stripes could be indeed eliminated by cleaning the zebrastripes - but the other thing, that the whole display fade away...After turning off/on, it´s back again - And fade away after a while..Or it is a kind of adjustment in the menu - Before I´ve played a lot in it to test the new touchpanel...RTFM I guess.Martin

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 14, 2023, 12:26:27 am
content: That fading over time, I would look at the contrast control circuitry. I know the Tek TDS200 scopes have a 50K thermistor after the contrast control signal from the MCU (that is referenced to a TL431) to help counteract temperature drift in the LCD.Also, you could maybe try the ol' LED conversion with some thin LED strip?I have a bunch of this stuff that I have used to great success in my Tek THS720 scopes, and might have a go at using it in my TDS220 scope too. I can send you a piece for the cost of shipping once I'm back from holiday in a week or so if you like.https://www.aliexpress.com/item/4000912596869.html

author: Martin72
author_rank: Super Contributor
timestamp: July 18, 2023, 10:25:43 pm
content: Hi,QuoteExactly that...When I was playing around with the touch panel, I must have hit the LCD on/off function.When on "off", the display turns off after about 10sec...Goes back on when you touch something somewhere on the field...Arghh.

author: Martin72
author_rank: Super Contributor
timestamp: July 19, 2023, 06:46:24 pm
content: Quote from: Martin72 on July 13, 2023, 08:14:09 pmThis panel is absolute crap, not worth the money...The contacts are so porous that they virtually dissolve after one or two times.What had previously worked via touch, now no longer works, only a few fields.So much money for such a crap....Maybe I'll manage to fix it.But I would prefer a completely new solution for the touch panel and display.

author: Krisztián
author_rank: Contributor
timestamp: August 10, 2024, 01:26:30 pm
content: Have you since managed to repair the touch panel somehow, or find a good quality replacement part? Or is it simply possible to operate the instrument via the serial port after switching it on, without having to press anything on the display?

author: Martin72
author_rank: Super Contributor
timestamp: August 10, 2024, 01:45:45 pm
content: Hi,In the meantime, I passed it on to a forum "colleague" a few weeks ago, maybe he can write something about it.With the Hioki LCR software, which incidentally also works on Windows10, you can control some things, but by no means everything.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 10, 2024, 02:04:13 pm
content: Thanks, Martin!I spoke with a seller on AliExpress last night, and we went back and forth with measurements and stuff, and he said this LED backlit LCD should work. If it doesn't I'll send it back, but I'm hoping it does work so I don't need to use the old backlight style. This new panel doesn't need any extra connection for the backlight.I also ordered a touch panel that claims to have a 1 year warranty.I will share links if the parts work out.

author: Martin72
author_rank: Super Contributor
timestamp: August 11, 2024, 07:41:57 pm
content: QuoteThis makes the backlight on/off function in the menu obsolete.Unless you satisfy the monk in one and link the circuit with the LED lighting....No, it doesn't have to be.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 11, 2024, 08:15:43 pm
content: Quote from: Martin72 on August 11, 2024, 07:41:57 pmI think I'll be okay, I wouldn't turn the backlight off anyway. 😉My only (minor) concern is that the new LCD has the contrast adjustment as a potentiometer on the back of the LCD. Assuming the LCD works, I'm curious if the front panel contrast knob will do anything anymore.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 11, 2024, 08:22:57 pm
content: While I'm waiting for the replacement parts to arrive, I repaired the front panel.There was an obvious crack/break at the top of the panel, but there was another major crack hiding at the bottom. I also found another small crack hiding at the top later in the process of repairing the panel.To start with, I broke the panel apart at the cracks so I could clean and then properly repair them. I used JB Weld Plastic Bonder, and it appears to be solid now.Once the glue was cured, I added 3 1.5mm acrylic pieces to give additional stability where the cracks were. Once it was all cured, I sanded down the glue on the front, and now it's good to go....outside on my deck in the sunlight inside a bag covered in "SalonCare 40 Volume Creme" to hopefully whiten the panel better. YouTube makes me thing it will work. We'll see. 🤷

author: Martin72
author_rank: Super Contributor
timestamp: August 11, 2024, 08:30:45 pm
content: I had fixed the crack above the display with an adhesive that we also use for fixing components that are used in armored vehicles....I don't know if it would have been necessary to repair it again.QuoteSee last picture there:https://www.eevblog.com/forum/repair/hioki-3532-50-lcr-schematic-service-manual-wanted/msg4572913/#msg4572913This will then be superfluous.

author: Martin72
author_rank: Super Contributor
timestamp: August 11, 2024, 08:35:15 pm
content: Quotehttps://www.eevblog.com/forum/repair/hioki-3532-50-lcr-schematic-service-manual-wanted/msg4613011/#msg4613011This was the result of intensive irradiation with UV light and the use of hydrogen peroxide.I can't imagine that a cream will give the same result.Either way, the problem is more likely to be protecting the now white front from yellowing, because obviously the white doesn't last long.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 12, 2024, 01:46:28 am
content: Quote from: Martin72 on August 11, 2024, 08:30:45 pmI fixed it because it was broken. 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 12, 2024, 01:53:17 am
content: Quote from: Martin72 on August 11, 2024, 08:35:15 pmThe creme is hydrogen peroxide, but being a cream helps it hold in place on the plastic, and it goes in a bag to stop it from drying out. It might not accomplish more than what the previous attempt did, but it's worth a try while waiting for things to arrive from China.What UV lamp did you use? I'd rather not leave it outdoors for a couple days if I don't have to.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 13, 2024, 06:35:52 pm
content: First attempt went better than I thought. 🤣In the youtube video I watched, the guy put the cream on with a brush. I was lazy and just lathered it on with my hand. I think the brush is better for a more even application, so I will do that for the next sunny day.I left it outside for 8 hours, but I think maybe only 5 or 6 had sunlight. Next time I need to use the opposite hand railing; that one stays in the sun longer. Oops.

author: Martin72
author_rank: Super Contributor
timestamp: August 13, 2024, 06:49:02 pm
content: Wow, just wow...

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 15, 2024, 10:38:04 pm
content: Some more progress. The screen looks nice, and the LED backlight indeed does not need separate power. It appears that both the contrast pot on the back of the LCD and the Hioki's contrast pot work.There's one probably minor flaw, and that's that the cable is soldered to the back of the LCD's PCB. The cable gets connected without twisting, which is nice.The LCD also seems to fit fine in the front panel.Also, it was packed nicer than anything I've ever received from aliexpress. Double boxed, doubled padded, and double anti-static too.

author: Martin72
author_rank: Super Contributor
timestamp: August 15, 2024, 11:02:25 pm
content: Judging by the stripes, you haven't adjusted its own contrast yet, have you?

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 15, 2024, 11:13:40 pm
content: Quote from: Martin72 on August 15, 2024, 11:02:25 pmI'm talking to the seller now to deal with that. I've tried adjusting both contrasts, but it's hard to get a perfect balance. I think the cable connection is poor.Interestingly enough, they also include an extra IC chip, which he told me to solder in to try and help with it. I soldered it in, and the dots look better at least.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 16, 2024, 12:06:42 am
content: The seller has been trying to rectify this, but of course I just got a message limit error from aliexpress. 🙄🙄 Try again in 24 hours. 💩 That blocked sending attachments, not the actual chat. Still annoying tho.He had me remove the contrast knob on the back of the LCD, and then the chip he previously had me add. He said the IC chip was for negative pressure voltage related to contrast.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 16, 2024, 01:03:08 am
content: I was fairly convinced the soldered-in cable was part of the issue, so I removed it. Then I removed the cable connector from the old LCD, and installed it on the new LCD.What was on the display improved a little, unfortunately though, I had to use the old cable which was also damaged. I ordered some new cables from Amazon, and I'm hoping that does the trick.I also suspect that the contrast pot on the LCR should maybe be replaced. I might do that also.ETA: Nope. I pulled the pot and tested it, and it works fine. It felt a little loose before, maybe reinstalling it helped. I'll find out in a couple days when I get the new ribbon cables from amazon.In any case, the seller has been helpful and quick to respond the whole time. This is the LCD I bought:https://www.aliexpress.us/item/3256802097838920.htmlThanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 16, 2024, 06:18:07 pm
content: The touch panel I ordered arrived today. Totally useless, does nothing at all. Oh well. On to the next one.

author: Martin72
author_rank: Super Contributor
timestamp: August 16, 2024, 06:42:13 pm
content: Fu...However, even at the risk of you hitting me:I almost went insane back then, as it now belongs around, the first time I plugged it in wrong, so that the contacts went empty (not occupied).

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 16, 2024, 07:54:53 pm
content: Don't worry, I had the same thought.The longer cable goes to the farther connector. But I plugged both cables in to both connectors, and even tried both ways again after flipping the new touch panel around so both cable connections were tried with both sides of the panel. It's junk.Then I plugged the original stock panel in, and it still partially works.The funny thing is, that the original panel works in one area, while the panel you tried to replace it with worked in a different area. The new one didn't work at all.

author: Martin72
author_rank: Super Contributor
timestamp: August 16, 2024, 08:19:45 pm
content: What annoyed me was that there was no data sheet for the touch panel.This is a resistor matrix, no “hard” commands are sent to the board through it, but voltage dividers are generated.At least that's what I think with a resistive touch panel.What I want to get at is that you can measure the panel to make sure that the error is not somewhere on the board (which I don't believe).But you need to know how the pins are assigned.Therefore.... data sheet.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 16, 2024, 09:57:15 pm
content: There are 6 X and 6 Y traces, and there's some other weird stuff going on, like one line that circles the whole pad and maybe connects X and Y at some point. The common feature that I've seen so far is that they all suck. 😉Finding a decent LCD screen was too easy, so I think the touch panel will remain a pain in the 🫏.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 17, 2024, 01:20:26 am
content: I just noticed something. If you compare the original to the common replacement versions, the replacements have an extra trace.

author: zepto
author_rank: Regular Contributor
timestamp: August 17, 2024, 01:40:16 am
content: This is a nice LCR meter. Is it not possible to control it with GPIB? Seems like a lot of effort if there is an alternate interface available. An external interface would also allow you to plot sweeps.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 18, 2024, 12:55:15 am
content: It mentions external I/O in the manual, but doesn't specify any standards (that I saw in the 4 seconds I skimmed that section).If it can be used remotely with something like TestController, that would be cool, but I'm not likely to use it if I can't get the touch panel to work. I think I will eventually.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 18, 2024, 12:56:24 am
content: Oh yeah, some dummy wasn't paying attention and bought new cables with .5mm pitch instead of 1mm pitch. Oops. The wait continues.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 18, 2024, 01:43:44 am
content: I scanned both sides of the original touch panel. You can see it's generally different than the other attempted replacements. One cable has six traces that apply to horizontal sense, and the other has 6 traces for vertical sense, plus one trace that goes all the way around and connects two pins.Many of the replacements that don't work, have placed one of the horizontal sense points on the opposite side of the panel. I don't think this would work anyway, unless you knew how to recalibrate the touch panel.Does anybody know how to calibrate these panels?

author: zepto
author_rank: Regular Contributor
timestamp: August 18, 2024, 03:09:42 pm
content: Quote from: KungFuJosh on August 18, 2024, 12:55:15 amI understand, and I did not mean to be dismissive of your efforts. I meant the capabilities of this device aren't really exploited by the touch screen interface. It still has value, assuming an external interface is available, even if the display and touchscreen are completely broken. If you give up, do not throw it away.I will have a 3531 soon. It is a couple revisions behind your model (3531->3532->3532-50) and has a GPIB interface. Assuming it isn't completely destroyed in shipping, I will write some programs for it. I can share them with you if you are interested.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 18, 2024, 03:21:34 pm
content: Quote from: zepto on August 18, 2024, 03:09:42 pmI didn't think you were being dismissive at all. I just doubt I'd use the device much if I can't get it working properly.I would love to see what you come up with. Do you use TestController at all? It's a great program. If we could add support on there for these devices, that would be awesome.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 18, 2024, 03:22:47 pm
content: I just got an original touch panel on eBay for $78 including shipping. It's lightly scratched, but works fully according to the seller. We'll see!

author: Martin72
author_rank: Super Contributor
timestamp: August 18, 2024, 09:19:02 pm
content: Quote from: zepto on August 18, 2024, 03:09:42 pmThis Hioki has a RS232 slot (instead of GPIB), I have made a corresponding cable (25-pin to 9-pin).It can be controlled with the software that can still be downloaded from Hioki, it even works with Windows 10 without any problems:https://www.eevblog.com/forum/testgear/schematicservice-manual-for-hioki-lcr-3532-50/msg5238030/#msg5238030The device “obeys” SCPI commands, so integrating it into the “Test Controller” software environment should not be a problem.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 21, 2024, 06:31:20 pm
content: The LCD situation is interesting. It's obviously not terrible in the photos above, but it's not perfect either. The seller has been trying (along with the help of his engineer) to make it better. Today he had me remove R13, and jumper J26. That didn't help, so the engineer wants me to increase the resistor values of R1, R2, R4, R5 from 222 to 302. I had to order an 0805 resistor kit since I didn't have that value on hand, but I should have it tomorrow.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 22, 2024, 06:49:13 pm
content: No improvements yet. It appears they were trying to improve the display quality by adjusting the contrast center point.I figured that out quickly because I tried 3.3kΩ, and it was immediately too high contrast. Switched down to 3kΩ and it was adjustable again, but looked like the attached.I asked them if there's something else that affects flickering or filtering we could change. Or if they have other ideas. 🤷

author: Martin72
author_rank: Super Contributor
timestamp: August 22, 2024, 07:00:35 pm
content: Do you have a data sheet for the display?It also looks like information is missing on the left, which can't be due to the contrast.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 22, 2024, 10:52:34 pm
content: I don't. I might ask for one. Though I might have set something weird when messing with different touch screens. 🤷ETA: I'll add a connector back to the original LCD and see if it's any different if the touch panel takes too long to get here.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 25, 2024, 02:29:43 am
content: Here's the original LCD connected. No data showing there either. The contrast looks great though. 🤷

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 25, 2024, 03:17:34 am
content: The LCD seller said the engineer should have a Hioki to test the LCD on in a few days. Hopefully, he'll get what he needs out of that to tell my dumbass what to change to make this work properly. Otherwise, I'll need to return it and get the old style LCD instead.

author: Martin72
author_rank: Super Contributor
timestamp: August 25, 2024, 12:54:58 pm
content: Quote from: KungFuJosh on August 25, 2024, 02:29:43 amThat was my mistake, if no parameter was selected (“off”), then nothing else is displayed, which also makes sense.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 03:49:03 pm
content: Progress?Their engineer suggested the following changes:R1 392R2 472R3 823R4 622R5 392R6 822Unfortunately, the resistor kit I bought was limited, and I don't have the 39, 62, or 82 variants. So I tried with 33, 56, 75 instead.This is what it looked like:I also replaced the 10k pot on the PCB with a 25k trim pot. The original pot was mechanically unhappy. It's more stable now with the trim pot. I might try and find the replacement 10k pot, but, eh, I don't know if it's worth the effort.Since the change made some improvements, I tried changing R4 to 7.5k and that helped horizontally, but not vertically. So I tried changing R3 to 100K, and it was too much. Now I'm ordering a better resistor kit to put the suggested values in. I'm much more confident in the possibility of this working now though.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 04:23:25 pm
content: I screwed around some more, and it got a little better:Suggestions -> substitutions:R1 392 -> 4.7kR2 472R3 823 -> 100kR4 622 -> 7.5kR5 392 -> 4.7kR6 822 -> 10kI might try a 5.6k at R2. I ordered the resistor set, but that doesn't come untiltomorrow. 😉The 25k trim pot is useless with those values. It has be set to contrast fully on to see what's there. I know I have other trim pots...somewhere.I'm guessing/hoping that tomorrow with the correct values, everything will look betterer.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 05:26:37 pm
content: This is getting interesting. I changed R2 from 4.7k to 5.6k, and it shifted the contrast center so that the trim pot became useful again. The image still wasn't great, so I increased it to 7.5k and we have better contrast, and more usable range on the trim pot.However, that shifted a vertical section out:Since I'm guessing, and don't have a schematic or datasheet to go from, I'm going to experiment with R4 next and see what happens if I increase that value.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 06:19:15 pm
content: After some more experimenting, it looks pretty good!Here's my current R values:R1 5.6kR2 7.5kR3 100kR4 5.6kR5 7.5kR6 10kI'll ask the seller to ask the engineer if he thinks that can be improved upon.Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: August 26, 2024, 07:25:41 pm
content: Could you please take a good photo of the board side of the new display?

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 08:18:17 pm
content: Sure, but please ignore my sloppy soldering. I was experimenting at high speed. 😉Here's the changed areas from the original:

author: Martin72
author_rank: Super Contributor
timestamp: August 26, 2024, 08:46:28 pm
content: You could ask the supplier for a circuit diagram, he should have one.In the meantime, the contrast thing has become clearer to me, the corresponding potentiometer on the Hioki should no longer have anything to do with the actual background lighting.The potentiometer will go to pin13 in the original display.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 09:03:59 pm
content: Quote from: Martin72 on August 26, 2024, 08:46:28 pmContrast doesn't affect the background lighting at all. Contrast affects the darkness of what's on screen. For example, in the attached (outdated) images, the LCD brightness is unchanged. Only the contrast is changed. It was either too light or too dark with no middle ground where the image on the screen looked good.

author: Martin72
author_rank: Super Contributor
timestamp: August 26, 2024, 09:06:32 pm
content: QuoteThat's what I wanted to say.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 09:30:09 pm
content: I had a feeling it was a 'lost in translation' thing. 😉I'm hoping to improve the result a little more, but if where it is is the best I can do, I'd say it's good enough.I got the next replacement touch panel today. Junk. The seller lied about it, and now I get to deal with that and try to find something better.

author: Martin72
author_rank: Super Contributor
timestamp: August 26, 2024, 09:39:40 pm
content: A circuit diagram would be helpful, try your luck with the supplier...I'm a bit surprised at the moment that it's such a “problem” to display the characters properly.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 10:04:47 pm
content: I was surprised at first as well, but I'm not anymore. Hioki clearly designed it a specific way with a specific LCD panel, and getting a modern LCD to match that isn't as straight forward as I thought. At least not for whateverthisLCD was designed for.I already asked for a schematic and they said they didn't have one. Which might might mean "they don't have one they'll share." 🤷

author: coromonadalix
author_rank: Super Contributor
timestamp: August 26, 2024, 10:48:34 pm
content: all theses resistors things must play with duty cycle, timings etc ... it's a matter of finding the row and column drivers data sheet if they exists and try to figure out ...

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 26, 2024, 11:15:15 pm
content: Quote from: coromonadalix on August 26, 2024, 10:48:34 pmExactly. Here's my notes so far:R1 392 -> 4.7k -> 5.6k (increase shifted contrast center further after adjusting R2)R2 472 -> 7.5k (better contrast center / more range with trim pot)R3 823 -> 100kR4 622 -> 7.5k -> 10k (bad - more flicker) -> 5.6k (less flicker)R5 392 -> 4.7k -> 5.6k (vertical lines partially returned) -> 7.5k better!R6 822 -> 10k

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 27, 2024, 02:37:08 am
content: I just ordered another touch panel from eBay (already got a refund from the junk one). This one is supposedly new, and the trace pattern looks more like the original.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 27, 2024, 03:30:05 am
content: I don't know if I'll bother replacing the original pot or not, but if anybody else needs one...It's fromALPS, 10kΩ, and appears to be from their RK09L series (or at least very similar). However, it's a 35mm shaft, and 3B taper.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 27, 2024, 09:57:33 pm
content: I got a better resistor book in today, and tried the engineer's suggested values. They were worse than what I came up with. I tweaked the values a bit, and now I'm about where I was before as far as it looks.This was today:R1 392R2 472 (not enough contrast range) -> 5.6k (better)R3 823R4 622 -> 5.6k (better but still a little flicker) -> 4.7k (better)R5 392 -> 7.5k (too much Vertical line contrast) -> 5.6k (too much? has Vertical ghosting) - 4.7k still some minor ghosting but betterR6 822I asked the seller to ask the engineer the specific function of each resistor so I can stop guessing on the others. Hopefully, he actually gets me that info.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 27, 2024, 09:58:52 pm
content: This was with the suggested values. It looks better in some ways besides the glaring issue. If I knew all the specific functions, it might actually come out well. 🤷

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 04:13:22 am
content: I don't know if it's interesting, or annoying, but there's clearly a relationship between R1 and R2. Nothing looks better than R1 at 2.4k with R2 at 6.8k, but R1 at 1.2k with R2 at 7.5k is very close. In either case, the bottom right corner fades out.With R1 at 2.4k and R2 at 5.1k, those vertical lines looked better, but the rest looked like crap.R2 also shifts the contrast center, so there's more adjustable range with the contrast knob when R2 is higher. But the higher R2 goes, the more it screws up the verticals controlled by R1.I think / hope that one of the other resistors has an effect on the relationship of R1 and R2.R4 value has an effect on the flicker. I didn't notice any other changes when I adjusted R4.R3 and R6 I have no clue about, but when I tried to change R6 it had almost no effect using a pot.R5 previously did affect the vertical lines. I'm going to tweak that next and see how it goes. 🤷Right now I have:R1 1.2kR2 7.5kR3 82kR4 4.7kR5 3.9kR6 8.2k

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 04:26:33 am
content: R5 definitely improved the situation. I don't know if I want to tweak it anymore. I might try 5.1k if I get bored.Current values:R1 1.2kR2 7.5kR3 82kR4 4.7kR5 4.7kR6 8.2k

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 04:50:40 am
content: R5 at 5.1k is definitely better.Now I should go to bed 2 hours ago. 😬

author: coromonadalix
author_rank: Super Contributor
timestamp: August 28, 2024, 05:30:20 am
content: the best results so far

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 28, 2024, 05:40:27 am
content: You almost need a breakout board like a mini 'mixing desk' of trimpots to tweak and dial them in to get it perfect, then substitute with the closest fixed values.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 28, 2024, 12:52:08 pm
content: loll yep had the same toughts .... but i would say somewhat usable like this ... depends of the OP lollseems a bit weak in the lower corners ?@KungFu can you show us the chip markings for the row and column drivers ? u9 u10 u11 too ?

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 02:09:43 pm
content: Quote from: coromonadalix on August 28, 2024, 12:52:08 pmA pot doesn't work in every position. R1 was okay, R6 did nothing, and I think R5 hated not being a fixed value for some reason. 🤷I definitely think it's easily usable now, but I might try 5.6k in R5 as R5 seems to directly affect those corners. My only concern is that it might cause some more ghosting. I also think it looks better in person than in the photos.In reply #110 above, there's a high resolution attachment you should be able to view the chip markings on (the one with the -min suffix).Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 03:07:06 pm
content: Here's a real photo with R5 increased to 5.6k. Contrast is at max but stuff still looks like crap, and now I would need to adjust R2 to shift things over and continue chasing the perfect balances. 🙄

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 04:56:38 pm
content: On a side note, the resistor book I got is bullshit. Supposed to be 1%, but I don't have any 1k resistors because they're all 1.2k marked 1001. 🙄

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 06:41:47 pm
content: After further experimenting, I went back to:R1 1.2kR2 7.5kR3 82kR4 4.7kR5 5.1kR6 8.2kThere's some very minor ghosting, but overall I think it looks great.Here's the thing though. I originally was going to keep this, but now that I have an IM3570, I no longer need it, and I don't have the space for both anyway.I have another touch panel on the way, and if it works, I'm going to sell this. So the question is, hypothetically, would you buy this LCR with how the screen looks in this photo? Or should I scrap it and try and get an original replacement LCD instead?If the new touch panel doesn't work, I'll probably sell it for parts/repair, as I'm spending too much time on this, even if it was entertaining. Somebody with better skills & more ambition can try and improve it further if they want. 😉Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: August 28, 2024, 09:34:50 pm
content: I would stop worrying about the little bit of ghosting and concentrate fully on the touch panel.As far as I can see, the ghosting is far removed from the 4 displayable parameters.I still find it fascinating that the display didn't work the way you'd want it to right away, especially since it's explicitly offered as a replacement.I also don't believe that the supplier doesn't have a circuit diagram for it, if he can give recommendations for resistor assemblies in the same breath.That's typically Chinese: they copy themselves like world champions, but don't give anything away in return.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 10:02:28 pm
content: Quote from: Martin72 on August 28, 2024, 09:34:50 pmI agree, I think I'm over the minor ghosting. I looked at the stock panel again, and it has a giant rectangle behind the entire display, and the contrast only looks darker because it's not backlit. If you zoom in you can still see the pixelation, and some thin vertical line gaps. I think the illumination shining a light on that stuff made it stand out more.Quote from: Martin72 on August 28, 2024, 09:34:50 pmIt isn't offered as a replacement. The seller suggested this LCD as a replacement based off the dimensions and the generic model number of the stock panel. It's not advertised as being specifically used with the Hioki.I also don't know how much they know about it. My guess is that they may have purchased the design files and manufactured based on that rather than having anything to do with the design of the product. They showed me a screenshot that clearly came from PCB design software, but they didn't seem to, or at least didn't admit to, understanding what the resistors do better than I understand now...and my understanding is still limited.I did a reverse google image search of the back of the LCD, and the panel came up with a few different model numbers, but clearly the same panel. Most of them were more expensive too. Still no datasheets for any of them.ETA: The ETA of the new touch panel is Mon or Tuesday next week. I hope it's a good one!

author: Martin72
author_rank: Super Contributor
timestamp: August 28, 2024, 10:12:06 pm
content: QuoteWhat was it advertised as, how did you find out about it?Plus:Powertip did not explicitly advertise the PG320240 as a display for the Hioki only.Hioki only used it for its own purposes without changing anything.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 10:28:37 pm
content: Quote from: Martin72 on August 28, 2024, 10:12:06 pmI googled the part numbers, and similar stuff came up. Then I messaged the seller to see whether the LCD I found was compatible or not. It wasn't, so he suggested this one instead.I couldn't tell you for sure why any of it is the way it is. Do we know for sure that Hioki didn't have Powertip customize any parts of the panels?ETA: I should add, I think the sellers level of understanding when suggesting the replacement was based on the physical measurements more than anything else. 😉

author: Martin72
author_rank: Super Contributor
timestamp: August 28, 2024, 10:35:49 pm
content: QuoteI would almost blindly say that this is not the case, because what is the current problem?The contrast, or....And that is a matter for the display.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 10:38:55 pm
content: It's not just contrast. It's:Quote from: coromonadalix on August 26, 2024, 10:48:34 pmAnyway, it's in a pretty good place now. Easy to read and stable.

author: Martin72
author_rank: Super Contributor
timestamp: August 28, 2024, 10:53:22 pm
content: QuoteIf we had a circuit diagram, we would really know.That is one point.The other is that, in contrast to today's displays, they were still rather “raw” over 20 years ago.The graphics/character generation was on board, in this case 4 bits were “pushed over” to the display in parallel.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 11:18:59 pm
content: Sure, but the new LCD didn't exist 20 years ago, and I assume was built with expectations of newer applications. So maybe that's where the need for changes comes from. I dunno, we'll likely never see a real circuit diagram anyway. 🤷

author: Martin72
author_rank: Super Contributor
timestamp: August 28, 2024, 11:24:33 pm
content: QuoteThe data stream from the controller to the “raw” display has nothing to do with the display quality, neither 20 years ago nor now.The only thing that might have changed is the TTL level, from the former 5V to 3.3V.I'll figure it out, I'm afraid....Good night.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 11:27:20 pm
content: Quote from: Martin72 on August 28, 2024, 11:24:33 pmI look forward to your findings. 😉Gute nacht.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 28, 2024, 11:31:53 pm
content: this is the main drivers ic's, check on the page 8, 10, 11 and note 2 ...

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 28, 2024, 11:42:32 pm
content: Thank you, but I don't know how to make any sense of that without a schematic. Even still, it might be above my paygrade. 😉R1 - R6 are all mostly interacting with theLM324chip, and then some tantalum capacitors. What happens after that, I dunno.

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 29, 2024, 01:14:33 am
content: Take a look at pages 8, 11 and 30 of the datasheet coromonadalix posted, it might help get you started.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 01:37:49 am
content: I did, but...Quote from: KungFuJosh on August 28, 2024, 11:42:32 pmLooking at those charts doesn't tell me any specific details about what component/value I would need to change to reduce the minor ghosting present. 🤷

author: coromonadalix
author_rank: Super Contributor
timestamp: August 29, 2024, 01:44:23 am
content: some notes on p15 p163. V0, V12, V43, V5 pin4. VLCD = VDD - VEE, V0 = VDD = 5V, V5= VEE = -23 VV12 = VDD-2/n(VLCD), V43 = VEE+2/n(VLCD), n = 17 (1/256 duty, 1/17 bias)5. V0 = VDD, V12 = 1.71V(VDD = 5V) or -0.06V (VDD = 3V),V43 = -19.71 V(VDD = 5V) or -19.94V (VDD = 3V), V5 = VEE = -23V, no-load condition (1/256 duty, 1/17 bias)i never saw an lcd with the same ic's for column and row, for sure the voltage thing is something ..... scratching my headand the missing 8 pins soic,some of them or one of them would-could be a negative supply generator (i think) not installedmaybe theses calculation may help to fine tune the resistors ? and the lm324 could act as buffer(s) something since it's a quad op amp

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 01:53:13 am
content: U8 is "negative pressure" according to the seller, and it's currently installed. The seller told me to try it again. It didn't affect the ghosting, butmaybemade the flicker worse. That is to say, the flicker wasn't noticeable with my other values, but now there's a hint of it with U8 installed.ETA: I reduced R4 to 3.9k and the flicker is gone with U8 installed.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 29, 2024, 10:24:28 am
content: maybe in all of this it's a matter of getting the multiples voltages and get the right duty cycles ... you have to check your older lcd to see at what it was, and fit the new as suchcould be some timing issues at some point for the ghosting when it happensthe Hioki must use strict settings, and most of the glcd 320x240 could be out of it, there is so many on the market, so many ic's etc ...to fit with the motherboard SED1335F driver, it work at 1/2-duty to 1/256-duty LCD drivemaybe at some point, you may have to live with it like thisyour original Powertip can be found (post #14), but some say compatible on ebay, but over 75$ is a huge rip off

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 02:36:08 pm
content: I could definitely live with it as it is if I was going to keep it, but I'm not. The next owner will need to live with it or make it better if I can't.I think in person it already looks better than the original LCD. The ghosting can definitely be tweaked, but I had to return the resistor book I had. They were supposed to be 1%, but were more like 5% to 20%+. I ordered another book, and hopefully that one will be better.I raised R3 to 100k, since that was the only higher value I had floating on my workbench, and that made everything besides the R1/R5 vertical lines basically disappear. When the new resistor book comes, I'm going to try lowering it. If I can make the general stuff darker without changing R2, then I think that may lead us somewhere better. R1/R2 definitely have a relationship that makes it impossible to tweak one area without affecting the other. I'm hopeful because the R3 change didn't appear to have any significant effect on the ghosting.Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: August 29, 2024, 02:51:49 pm
content: Have you ever tried to clean the original display, i.e. these “zebra stripes”?I didn't trust myself to do that, so I preferred not to touch anything.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 04:07:12 pm
content: Quote from: Martin72 on August 29, 2024, 02:51:49 pmNo, even if I somehow made that better, the lack of a backlight makes it not worth the time. I really like the idea of the modern LCD with the LED backlight anyway.I'm pretty confident about R3 shifting this somewhere where I can get the contrast better without the ghosting. I'm going to try a pot, and hopefully it behaves. 😉 ...otherwise I need to wait until tomorrow when the new resistors should arrive.ETA: A pot was useless, but alligator clips worked with THT resistors. Lowering R3 improved the general stuff, and had no effect on the ghosting. Still experimenting.ETA2: R3 at 68k seemed improved, but then lowering R5 went wonky. I'll wait until tomorrow for the resistors to arrive.

author: Martin72
author_rank: Super Contributor
timestamp: August 29, 2024, 08:45:28 pm
content: QuoteLED lighting can be retrofitted there, see layout.I'm really surprised that you have to tinker so much with a new display.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 10:00:37 pm
content: Quote from: Martin72 on August 29, 2024, 08:45:28 pmMe too. If I had to guess, I would say it's probably because the values the guy suggested were maybe not great. They said they borrowed "the same device" to test it with and it worked with those values, but they conveniently didn't take pictures, and they already returned the LCR. 🙄When I get the new resistors, I'm considering going back to the original values and tweaking from there.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 10:28:39 pm
content: Hmmmmmmmmmmm. I started looking at some of the same LCDs from other sellers, especially on eBay. It seems they have less populated. 🤔ETA: it looks like most of that "extra" stuff is related to U8. Without U8 I guess R7 - R10, L1, D1, etc. are useless.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 29, 2024, 10:57:00 pm
content: maybe becauseon some systems, the main board is providing the negative voltage, had a few who needed at least -21 to -25 vdc to have good contrasti managed to find some small tdk miniature smps and fiddled soldered it on the glcd ...what annoys me is: when they say "compatible" and they don't provide what you need to make them work

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 29, 2024, 11:12:41 pm
content: Yeah, if I understood anything about how LCDs work (don't really want to 😉) then maybe tweaking the "negative pressure" BS might be helpful. I dunno. It didn't really have any effect whether it was active or not regarding the ghosting anyway.

author: Martin72
author_rank: Super Contributor
timestamp: August 30, 2024, 09:47:35 pm
content: If you compare the two displays, you will notice the complete absence of the “fat” capacitors in the original, even if there are corresponding assembly options available.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 30, 2024, 11:44:15 pm
content: Good news, and bad news.The bad news: the new LCD basically decided to get cuckoo last night. It's probably useless, and will most likely get returned.The good news: I found a touch panel that works! There was no data before because I apparently managed to set the trigger to external. 😉

author: Martin72
author_rank: Super Contributor
timestamp: August 31, 2024, 12:12:09 am
content: QuoteYeah !

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 31, 2024, 12:16:20 am
content: Quote from: Martin72 on August 31, 2024, 12:12:09 amI'm pretty happy about that. That seemed to be the harder thing to find.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 31, 2024, 01:46:50 am
content: The seller I bought the touch panel from also sells averysimilar LED backlit LCD panel, and actually advertises it as being for the Hioki 3532-50. I sent him an offer, I'll probably wind up getting it from him. I'm interested to see if it works 100% or has similar issues.ETA: Ordered.

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 05, 2024, 06:58:09 pm
content: I only have a minute, so I'll just throw this right here...

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 05, 2024, 08:26:47 pm
content: For anybody who needs a new touch panel or LCD, goldenworld8811 is the seller on eBay I got both from. When I ordered the LCD, they asked me to send photos of the front and back of the original LCD. The LCD they shipped is not the same as pictured in their ad, but actually matched the look/bezel of the original better. It's also a modern backlight, which is nice.LCD:https://www.ebay.com/itm/153333452030Touch Panel:https://www.ebay.com/itm/163477240213As always, my experience was good, but YMMV.Thanks,Josh

author: Martin72
author_rank: Super Contributor
timestamp: September 05, 2024, 08:33:23 pm
content: That looks very good now.Are you going to leave it as it is and deal with the device itself?

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 05, 2024, 08:45:12 pm
content: Thank you, yes, it's great as it is.It's got the internal contrast control (I swapped with a 10k as it was supposed to be). I doubt it should need to be adjusted with this LCD panel anyway. I tried contacting the manufacturer of the original pot, but never heard back. From the pot case to the end of the shaft is 35mm, and I couldn't find anything that is both a 9mm pot and that long. So I'm over that. I used some double-sided tape to mount the knob so it doesn't look goofy. Another option was to put something goofier there, but I opted not to since I'm not gonna keep it.It's already warmed up, so I'm doing open/short correction now and I'll see how it compares with the LCR Cal Test PCB. I'll post the results in that thread when I'm done.Thanks,Josh

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 05, 2024, 11:10:14 pm
content: Here's a couple more photos. The screen zoom feature is cute. I posted thetest resultsin the Cal Test PCB thread.