hybridfree/eevblog-posts huggingface dataset:
Crest Ultrasonics Drain Valve - Page 1
Forum section: electronics / repair

author: dfnr2
author_rank: Regular Contributor
timestamp: January 23, 2017, 09:11:27 pm
content: Low tech question here.I picked up a Crest Ultrasonics 2600HT benchtop ultrasonic cleaner, and it's missing the valve on the back that keeps the tank from draining out. Does anyone have any info on this valve? I think it's a 5/8" threaded connection on the back, but can someone confirm? Any suggestions on a replacement valve?Thanks!Dave

author: aargee
author_rank: Frequent Contributor
timestamp: January 25, 2017, 07:01:20 am
content: If you're unsuccessful then try this... on my US cleaner there is a latex drain tube and a clip to keep it above the level of the tank.When you're ready to drain, just let the tube drop down into the drain.

author: james_s
author_rank: Super Contributor
timestamp: January 26, 2017, 05:33:54 am
content: Do you have a real hardware store anywhere near by? Not like Home Depot but one of the little places that has actual hardware? That or a specialist plumbing supply place, you could take the cleaner there and probably find something that will work.

author: Psi
author_rank: Super Contributor
timestamp: January 26, 2017, 07:29:00 am
content: Ask Louis Rossman if he can order you one.He has become a supplier of Crest ultrasonic cleansers

author: DTJ
author_rank: Super Contributor
timestamp: January 26, 2017, 08:07:57 am
content: If the hole is about 16mm, roughly 5/8" then it could be a 3/8" 19 TPI BSP/T pipe thread - your local hardware should have a ball valve for $5 or $10.
JYE tech dso-068. - Page 1
Forum section: electronics / repair

author: cbgpedalmaker
author_rank: Newbie
timestamp: January 27, 2017, 02:24:28 pm
content: I know that JYE tech has their own forum, but it has not been any help. Has anyone here ever put together a JYEtech dso 068? I believe that the 'bob5' board on mine is bad. It is supposed to produce the -5v supply, but I am getting nothing out of it. I would love to get this scope going this weekend. I already have something to troubleshoot with it.

author: joseph nicholas
author_rank: Frequent Contributor
timestamp: January 27, 2017, 02:30:42 pm
content: I had similar problem with a DSO130 for JYE tech. I blew a voltage regulator giving the negative voltage. When replacing it the scope worked fine. If this scope came with an instruction sheet you could consult it for voltage checks. Good luch.
TR4131 Spectrum Analyser Problem - Page 1
Forum section: electronics / repair

author: Tony_T
author_rank: Newbie
timestamp: January 25, 2017, 04:22:02 pm
content: Hi All..I bought a TR4131 some time back as a non-worker and only recently had the time to check it out.It passes the Start-Up self test and boots fine. The default config settings appear onscreen but there is no noise floor trace.All controls appear to work and change settings as they should do.I have re-seated all boards and checked for any obvious component problems. There is a strange anomaly when the attenuator and reference are adjusted to the same ratio where they produce some kind of trace which is very strange.. erratic.. and off the screen in the Y plane.At first I could not get any signal to show onscreen but after correcting a bad rf connection from the 2nd IF Out I now do get a signal showing (of sorts) but still no noise floor is visible.To me I think the SA is working correctly except for the trace being over-scanned.I thought perhaps the crt has a mechanical problem with the yolk being misplaced but have not yet opened up the crt area as it is closed like Fort Knox and looks like a big job.Have done some testing of the attenuator.. mixers.. local oscillators.. log output.. and reference for expected frequencies and power levels and I am 90% happy with the results. The other 10% is because I do not have any information or schematics for the TR4131 to know if certain power levels are correct. However nothing jumps out as being badly amiss.Because the graticule and settings appear onscreen in the correct manner I am thinking that it is not a problem with the display logic but I could be wrong as my field is radio & satellite comms and although I understand how a Spectrum Analyser works I am not used to working on them.I've made 2 videos and uploaded them to show the problem in detail and they can be viewed at the below links.. In them I have detailed many things which would take some time to write here. So I think the videos will explain better.I hope it is ok to put the links..So guys.. any help.. ideas where to check next.. schematics are all welcome ;-)73TonyG7WHK
TEK TM 5003 foot - Page 1
Forum section: electronics / repair

author: frantisek
author_rank: Regular Contributor
timestamp: January 25, 2017, 02:19:06 pm
content: Hello, everyone! Has someone please foot cabinet:bot earth brown. 348-0617-04 for Tektronix TM 5003. I need 1. Color can be other than brown. Thank you.
Vacuum Tube Resource - Page 1
Forum section: electronics / repair

author: law_freak
author_rank: Contributor
timestamp: January 25, 2017, 04:26:03 am
content: I'm in the process of restoring the radio for a 1956 Oldsmobile Super 88 Holiday Coupe and stumbled on this incredible instructional video. Worth it for the music alone!Enjoy!https://youtu.be/igGu-I7Cg6A?list=PLo9Iv3P3GPsCJ76ID-LisSktTSd1o84vb
Parts exchange  - Page 1
Forum section: electronics / repair

author: mimmus78
author_rank: Unknown
timestamp: January 24, 2017, 10:26:02 am
content: How many of you has been forced to buy more than one chip (or other parts) when you only need one and most probably you will never need again in your entire life?Everybody here that is repairing stuff is full of parts that are "rare" and most probably stay on some drawer forever.Is there any parts exchange web site out there that will solve this problems to access rare parts in small quantity and with acceptable prices?

author: IonizedGears
author_rank: Regular Contributor
timestamp: January 24, 2017, 05:20:21 pm
content: Quote from: mimmus78 on January 24, 2017, 10:26:02 amEbay

author: mimmus78
author_rank: Unknown
timestamp: January 24, 2017, 06:48:01 pm
content: Hummm unless I'm very desperate I will not get a part from eBay ...Inviato dal mio Nexus 6P utilizzando Tapatalk

author: dan3460
author_rank: Frequent Contributor
timestamp: January 24, 2017, 07:52:39 pm
content: I have bought several ICs on ebay and never had a problem. I would not buy capacitors and if you buy resistors you can always check them before installing them. I have been buying when I see offers in a web site called electronics goldmine, seems to have decent quality and low prices.

author: mimmus78
author_rank: Unknown
timestamp: January 24, 2017, 08:49:31 pm
content: Well guys I'm not talking about resistors or capacitors.I'm talking mainly of some esoteric IC ...

author: james_s
author_rank: Super Contributor
timestamp: January 25, 2017, 03:50:11 am
content: I've bought loads of parts on ebay, everything from simple passive parts to esoteric and hard to find ICs. Out of hundreds of transactions I think I've only been burned once with some EEPROMs that turned out to be something else. Not even sure what they were, the nice shiny black and printing washed right off in acetone.
Scantronic alarm - transformer replacement - Page 1
Forum section: electronics / repair

author: Bicurico
author_rank: Super Contributor
timestamp: January 23, 2017, 10:29:27 am
content: Hi,I own a Scantronic 9448 alarm system and the transformer got damaged - the coil burnt due to a current spike.I went on eBay and bought a second hand transformer from a Scantronic 9600 system, which from the pictures looks exactly like the one I have. It has not arrived, yet.Meanwhile, it occured to me to look at installation manuals for both devices and I found out that the Scantronic 9448 manual referes to a 21VAC intput connector from the transformer, while the Scantronic 9600 manual has a 19VAC connector.My question is: what can possibly happen, if I connect the 19VAC transformer to my Scantronic 9448 board, which expects 21VAC? Is there like a +/-10% voltage tolerance? Or will the house burn down?Thanks,Vitor

author: Muttley Snickers
author_rank: Unknown
timestamp: January 23, 2017, 10:56:21 am
content: It wont know the difference and I would be very surprised if it complained, most systems can run on anywhere from 16VAC to 22VAC and I've measured quite a few unloaded transformers/ power supplies/ plug packs output being much higher than the label without detrimental effects.

author: Bicurico
author_rank: Super Contributor
timestamp: January 23, 2017, 10:59:48 am
content: Thanks for your reply.I opted to ask the seller for a cancellation and he just refunded me.I know nothing too bad would happen, but because this a house I am not living in, I felt even a minor risk was something I was not comfortable with.Regards,Vitor

author: james_s
author_rank: Super Contributor
timestamp: January 25, 2017, 01:38:21 am
content: The difference between 19 and 21V is less than 10%, that's well within the normal tolerance on something like that. Your line voltage may well vary more than that over time.
Frequency counter Advanced R5363 - Page 1
Forum section: electronics / repair

author: ua4yhz
author_rank: Regular Contributor
timestamp: January 24, 2017, 07:48:44 pm
content: Good day! Tell me please the name of the chip PWM controller and the power transistor in the power supply. Bought a frequency counter without these details. The rest of the burnt components have been replaced.For the scheme I would be very gratefulThanks in advance!
Locating HP 1N6609, 1N6610, and 1N6611 LEDs - Page 1
Forum section: electronics / repair

author: KJ-90
author_rank: Contributor
timestamp: January 23, 2017, 09:29:32 pm
content: I have a design drawn out on paper ( 1980s ) from my deceased civil engineer father ( +2011 ) which used the HP 1N6609, 1N6610, and 1N6611 TO-46 gold cased LEDs. The 1N6609 is red, the 1N6610 is yellow, and the 1N6611 is green. Each LED had a simple current limiting resistor in series with it ( I believe it was 470 ohms 5% ) for a standard 9V battery. I would like to build his circuit. However, I was wondering if anyone knows of a "general public" source for these devices. There are a number of industry sites which claim to have stock of them, but they are the North American "broker" sites, some are major well-known names. I was wondering if anyone knows of a business that is willing to sell a reasonable amount ( e.g. 4 of each color ). I've never dealt with anyof these "broker" sites before, and I am wondering which one(s) the community knows that help forum members who are not businesses.HP also made a far more common and smaller version of these LEDs with different specifications, which are somewhat easy to find. They are 1N6092 ( red ), 1N6093 ( yellow ), and 1N6094 ( green ). These devices come in TO-46 packages, but have lower If ratings and less light output. I had no trouble finding them from a known legitimate US eBay business, but what about the 1N6609-11 series types?

author: TAMHAN
author_rank: Frequent Contributor
timestamp: January 24, 2017, 02:19:07 am
content: KJ, first of all sorry for being a bit blunt about this. No disrespect is intended - my fiancee died many years ago, and I am divorced from my ex who also was a business partner, so I know well how it feels to handle the files of persons.But, may I ask why these diodes were selected? Given the abundance of LEDs, I would simply solder something together. In fact, wait a tiddle little bit...

author: TAMHAN
author_rank: Frequent Contributor
timestamp: January 24, 2017, 02:36:20 am
content: Hello,here, you might be able to find something:http://www.mouser.sk/Optoelectronics/LED-Indication/LED-Replacements/_/N-b1d1t/Am too stressed atm. But if you want, I can make a video how to bodge together a "replacement" also.EDIT 2.This below is wrong. These dont have the resistor!!!!EDIT Look here. Looks like MicroPak still makes them:https://www.arrow.com/en/products/1n6609/micropac-industries.Part numbers such as the one you mentioned, usually are government standards. So, in most cases, you can simply replace them with a part from another house.Tam
unsertinity calculation - Page 1
Forum section: electronics / repair

author: subeesh
author_rank: Newbie
timestamp: January 23, 2017, 02:37:47 pm
content: i would like t study unsertinty calculation

author: doktor pyta
author_rank: Frequent Contributor
timestamp: January 23, 2017, 02:52:26 pm
content: Google for 'uncertainty calculation', You would have much more results.

author: mission
author_rank: Contributor
timestamp: January 23, 2017, 06:38:23 pm
content: I second that.If this is what you're after.... here's a short paperuncertainty propagation through maths
Help: Anyone have HP 33120A function gen. ROM /firmware - Page 1
Forum section: electronics / repair

author: mzzj
author_rank: Super Contributor
timestamp: May 13, 2016, 08:53:38 am
content: This project has been on backburner for a while.I am running out of ideas what to check to save this from scrap bin.Does anyone have ROM image for this or is willing to unsolder the 27c020 eprom to read it?

author: mzzj
author_rank: Super Contributor
timestamp: May 15, 2016, 09:03:40 pm
content: Borrowed one working 33120A, desoldered the EPROM chip and programmed to new flash. Tried the new flash on my own 33120A, no success. Soldered orginal working flash to borrowed unit, this one gone dead too!Now both of the meters are equally dead

author: bitseeker
author_rank: Super Contributor
timestamp: May 15, 2016, 11:06:56 pm
content: Is the borrowed one still dead if you put back its original ROM? If so, perhaps the bad ROM has a short in it that damaged other components. That'd be a bummer.

author: lowimpedance
author_rank: Super Contributor
timestamp: May 15, 2016, 11:23:57 pm
content: HUH..........Does the now saved firmware burned into a new flash and re installed back to the originally working unit restore it back to functionality ?.

author: picburner
author_rank: Frequent Contributor
timestamp: May 16, 2016, 05:47:09 am
content: In this teardown it would seem that the eprom be two am29F010 flash.https://www.eevblog.com/forum/reviews/hp-33120a-teardown/In your 33120A is instead only a 27C020?it is possible that welding the memory back in the working instrument you've shorted a few pin or pin/track?Good luck.

author: mzzj
author_rank: Super Contributor
timestamp: May 16, 2016, 07:08:09 am
content: Quote from: picburner on May 16, 2016, 05:47:09 amI think that the chip and functionality is mistakenly identified in those teardown photos. there is a sticker over the firmware chip so I bet it also has 29F010 for user setttings(arb memory) and 27C020 OTP ROM for firmware.Things get more weird by day: now the borrowed unit (dead after firmware reading attempt) started working...Fix? let it sit on the table over night and it started workingWas the memory too hot when we tried it first time? No. it had plenty of time to cool and we tried countless times with no success...I don't think I made any shorts or dry joints, usually PLCC-32 is reasonably easy piece of cake for me.

author: coldframe
author_rank: Regular Contributor
timestamp: January 23, 2017, 02:35:45 pm
content: Quote from: mzzj on May 13, 2016, 08:53:38 amHello mzzjHere you are. Please, find attached file.I hope these help.ps.after download, change filename extention ("33120-88851.gif" -> "33120-88851.BIN")coldframe.
HP6632B Overvoltage problem [SOLVED] - Page 1
Forum section: electronics / repair

author: xtof
author_rank: Newbie
timestamp: January 22, 2017, 12:22:23 pm
content: Problem: 2 HP 6632B showing same error: overvoltage error when setting Vout to around 8V. Rest seems OK.Overvoltage is detected at U306, comparing Vout+ with a combination of Vprog (from the microcontroller) and DMON_COMP. Vprog comes directly from the uC board, measured OK. So the problem is DMON_COMP being to low. DMON_COMP comes from U313, in a buffer amp configuration with input IMON_H IMON_L and Vout-. On the 6632B IMON_H/L are not connected, so it is just Vout- that is buffered, probably to prevent floating of the Vout- versus Vprog reference. Vout- at the input was measured at 0V (pin3) OK, but U313 output is -13V, so the Opamp U313 is broken. Spares ordered from Ebay at around 5USD, and replaced. Problem solved.Christophe

author: bitseeker
author_rank: Super Contributor
timestamp: January 23, 2017, 03:20:33 am
content: Welcome to the forum, Christophe. That was quite the all-encompassing post. Thanks for sharing and following up with the solution.
What temperatur should I choose and which type of weld should I choose? - Page 1
Forum section: electronics / repair

author: edeweld
author_rank: Newbie
timestamp: January 22, 2017, 01:35:29 am
content: Hello Folks,I intend solder components in this board:http://www.jyetech.com/Products/LcdScope/e138.phpI need know what type of weld and what temperature should I use to build a great solder in leads on all components.I use this soldering station:http://www.velleman.eu/products/view/?country=be&lang=en&id=363894Best Regards,Sorry about my english, if you can't understand my point or have any question please tell me! Thanks

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 22, 2017, 12:06:21 pm
content: What do you mean by 'weld'? Do you mean the soldertype like leaded or nonleaded?Basic leaded solder (60/40) is good for hobbyist through hole soldering.But you may develop a different preference through experience.Temperature isn't very critical either.350 C is good starting point but you can go much lower.What does matter is how much heat you apply to the work and for how long. Heating components for more than a few seconds can damage them or the PCB' pads/traces.You want toheat up the work, feed in solder as soon as it melts and then remove the iron once you have enough solder for the joint.This is something you must learn by practice.Start with inexpensive kits first. Or just solder some scrap components to a piece of experimenting board first.I don't think your soldering station is reallytemperaturecontrolled.It probably is adjustable inpowerwith a dimmer like circuit.The controller will put a given amount of power into the iron and it's temperature will depend on how much heat flows out of it.In air this will be little and the iron will be hotter, once applied to the work it will quickly drop in temperature as heat flows into the joint.That means you must judge how big the joint is thermally.A small pad will need little power to get hot quick, a component with heavy leads or a large copper plane will need more power.This will be a matter of experience.

author: carl_lab
author_rank: Frequent Contributor
timestamp: January 22, 2017, 12:16:07 pm
content: Use standard solder Sn60Pb40 or SN63Pb37 at about 280 to 380 C.https://en.wikipedia.org/wiki/Solder

author: Brumby
author_rank: Unknown
timestamp: January 22, 2017, 01:21:03 pm
content: I built up one of these kits a few months ago - and I noted there were two versions supplied: One had all the SMD components installed (leaving only the through-hole components); the other had the 3 big SMD chips only pre-installed, leaving you the other SMD components to fit as well as the through-hole.From your questions, you would seem to be fairly new to the skill of soldering - and I would not recommend this kit as a first-time project and certainly not if you have the version with SMD components to fit.Mind you - that is only my recommendation. If you approach the exercise sensibly, you could have success.I would suggest you practice on something beforehand. Burning up an old board or scrap is a more palatable learning experience than frying your project PCB.
Generator Controller - High Current Indicated, with No Load. - Page 1
Forum section: electronics / repair

author: kolbep
author_rank: Frequent Contributor
timestamp: January 20, 2017, 07:37:12 pm
content: Hi All,Here is my next little repair project (or if it is not a fairly easy fix, it will just be replaced, it is for a customer, so I do not have unlimited time).It is a Generator Controller for a 3 Phase Generator.The generator would shut down after about 30 Seconds of running. I eventually managed to navigate the Chinese menu, to set it to English,and then I could see the problem. It was shutting down due to Overcurrent. Controller reporting over 1100A per Phase! almost Identical current reading for each phase. And that was with No Load, and with the output breaker switched off.The Generator has 3 CT's (1 per phase) connected to the controller. I disconnected the CT's from the Controller, and bridged out the CT Inputs on the controller, and was still geting over 1100A per Phase. Which means that the CT's are fine. I also tested, I have no leakage from the Phases to the CT's.So I know the problem is definately in the Controller. Here are pics of the Main Input PCBand a close up of the CT Input Section.The CT Inputs to the controller are rated at the usual 5A.If I look at the Board, I see that the Inputs go through the Black CT's that are on the board. The Black CT's connect to a Transistor (for some reason), and then to a TL0841 JFET OPAMP (U17). From the Opamp, they then go through a HEF4051B Mux/Demux (U19), and then goes to the headers to the microcontroller/display board.There are also Voltage inputs (and these seem to be reading fine).Now, If all 3 Channels are reporting the same (or similar) current, which is Very High, with the inputs shorted out, do you think that the Opamp or the Mux/Demux might be faulty. I just want a general idea of where to look. The Board does not have any signs of overheated or burned or damaged components, so I am flying blind until I get it on the bench tomorrow.And I Love the Series of SMD Resistors on the Voltage inputs, the long rows of them (for the resistors voltage limits) look very sexy.ThanksP

author: SeanB
author_rank: Super Contributor
timestamp: January 21, 2017, 08:24:26 pm
content: The transistor is there as a voltage clamp for spikes, and I would bet the opamp is dead from voltage spikes. Easy to check, give it a 5v supply in the appropriate pins and check the outputs are still around half rail.
American Arium ML4400 Logic Analyser Repair? - Page 1
Forum section: electronics / repair

author: dexters_lab
author_rank: Unknown
timestamp: January 21, 2017, 08:55:14 am
content: i have a Arium ML4400 logic analyser here, it's complete with pods and adaptors for the Motorola 68020 and 68030 CPUs, i am trying to figure out if it's worth a repair to resellIt powers up but it reports a nvram battery failure. If i can fix the nvram battery issue it could be a runner.Does anyone know anything about these systems? Like if the nvram failure means it's lost important cal data and is now a brick?

author: philpem
author_rank: Frequent Contributor
timestamp: January 21, 2017, 10:06:58 am
content: There's a bunch of Arium ML4400 stuff in the Xmission Arcade Archive, including PDFs of the manuals:http://arcarc.xmission.com/Test%20Equipment/Arium/AriumML4400/Doesn't look to be any service manuals sadly.

author: dexters_lab
author_rank: Unknown
timestamp: January 21, 2017, 10:46:23 am
content: Thanks Philjust been reading the user guides from that site, looks like it was a nice system in it's day and the nvram might just be for storing setup/config profileswith the 68020 & '030 pods it could be very useful to the right personi will open it up next week and see what the nvram actually is
Toshiba 32HL67U - Lightning Damage? - Page 1
Forum section: electronics / repair

author: Sceptre
author_rank: Regular Contributor
timestamp: December 04, 2016, 04:33:56 am
content: I'm trying to diagnose a broken Toshiba 32HL67U power supply. When I removed the V28A00030801 assembly from the TV, I noticed a couple burn marks on the chassis, corresponding to marks on the PCB (near R869 and R806) per the attached picture. Are these characteristic of lightning damage, or could they just be arcing from a malfunctioning supply? I don't want to put any more time and effort into this if there may be more damage downstream (as can be the case with a lightning strike).The first issue that I found with the PS was an open F802 (HOT_DC_MAIN to main DC-DC controller Q801). The replacement fuse did not blow, but there were still no outputs. I then determined that START_UP_SUB to QE01 was low and pulsating (when read with a DMM), though the voltage is steady on the other side of the dropping resistor (i.e. after the full-wave rectifier). It's not clear to me whether QE01 is broken or if an output short is causing it to cycle into shutdown. I checked cap ESR values (as seen in the picture, C816 and C827 were removed for testing) and diode/transistor junctions, but didn't find any problems. One burn mark is on the DRIVCC signal to Q801 (Pin 9); the other is on the 5V1 coil pin of relay SR81, which supplies AC to the HOT_DC_MAIN full-wave bridge. The pins are relatively long on the solder side, but there are plenty others which are just as long.Thanks for any insight or guidance!

author: amyk
author_rank: Super Contributor
timestamp: December 04, 2016, 04:01:16 pm
content: Lightning damage will be far worse than that.

author: Sceptre
author_rank: Regular Contributor
timestamp: January 21, 2017, 03:39:20 am
content: A belated thanks for that response, amy. Still looking for hints regarding how to isolate this failure. Anyone?
Using The Velleman K8042 dual rail pcb kit - Page 1
Forum section: electronics / repair

author: RNA
author_rank: Regular Contributor
timestamp: January 19, 2017, 02:49:55 am
content: This K8042 is an awesome and really cheap way to replace the psu on an old soviet synth from the 80's.https://youtu.be/sHWVADvntUI
Properly Made TP3 ( Tri-Lobe\Lobular ) Screwdriver Bits - Page 1
Forum section: electronics / repair

author: KJ-90
author_rank: Contributor
timestamp: January 18, 2017, 07:07:19 pm
content: I was wondering if anyone knows of an American, European, or Taiwanese made source for TP3 ( tri-lobe\tri-lobular ) screwdriver bits. These bits come in four sizes ( 2, 2.3, 2.7, and 3.2 mm ). However, they seem to be very difficult to locate from a reputable manufacturer. Almost all of the companies that make these bits are located in China or Hong Kong, and I'd rather not purchase those tools because of safety issues. I have read that people who purchase the related triangular TA14, 18, 20, 22, and 27 bits from those sources have had problems with bit breakage, and screw damage. There is also a similar issue with the TA series bits- there seem to be almost no American, European, or Taiwanese manufacturers. Only one American company sells US made quality TA series bits. Does anyone know of an American, European, or Taiwanese manufacturer for TP3 and TA series bits\screwdrivers?

author: helius
author_rank: Super Contributor
timestamp: January 18, 2017, 07:57:03 pm
content: Moody Tools (a division of Central Tools) makes a couple sizes of tri-point drivers. It appears that these are "Y1" type, and not TP3 or TA type like you asked.https://www.zoro.com/moody-tool-precision-screwdriver-tri-point-0x1316-51-2340https://www.zoro.com/moody-tool-precision-screwdriver-tri-point-1x1316-51-2339

author: janekm
author_rank: Unknown
timestamp: January 18, 2017, 08:34:15 pm
content: I can't find any specifically marked as TP3 but LA Bear from Taiwan and SEALS from Japan seem to be two non-mainland sources. Not easy to find reputable distributors though.There is variability in quality from mainland tool vendors too though, it should be possible to find some decent ones. Bits made from German or Japanese S2 steel tend to be decent (but will rust quickly if not oiled). You've got to avoid anything made for export though, there's a big difference between tools made for Chinese factories and those intended to be placed in a 120-bit pack sold for $1.

author: ve7xen
author_rank: Super Contributor
timestamp: January 18, 2017, 09:06:46 pm
content: I can't vouch for them but the Alpha brand from Sheffield Blades in Australia (hopefully as good as America) distributes aTP3 bit- 4mm size only. From photos on other sites it seems to be in-house production (they are stamped with the Alpha brand), though not sure of actual country of origin. They don't seem to be widely available outside AU/NZ.

author: tautech
author_rank: Super Contributor
timestamp: January 18, 2017, 09:17:38 pm
content: The onlygoodTri wing bit I have came from an aircraft engineer and it's an Air Tuf brand:AIR TUF PRODUCTS INC(602) 269-9741101 N 45th AvePhoenix, Arizona, USA 85043Historically Apex made top quality stuff too:http://apexbits.com/apex-tri-wing-screwdriver-bits.aspx
Power Designs Model 4050 Repair - Page 1
Forum section: electronics / repair

author: cspearow
author_rank: Newbie
timestamp: April 23, 2015, 06:48:59 pm
content: I just bought a Power Designs Model 4050 power supply. 0-40 V @ 5 A. It weighs a ton.The output voltage is fine, but the current limit has a problem. It shows 5 A when it's actually sourcing 150 mA, and it current limits accordingly.This shouldn't be too hard to figure out, but I can't find a schematic anywhere, for the 4050 or similar units from Power Designs. This seems odd, because it's a pretty popular line of power supplies.Does anybody have a secret source for Power Designs schematics or service manuals?-Carl

author: mzacharias
author_rank: Frequent Contributor
timestamp: April 24, 2015, 05:20:05 pm
content: Just a guess - maybe a burned resistor?

author: cspearow
author_rank: Newbie
timestamp: April 24, 2015, 08:46:23 pm
content: I think I found the problem.There is a wirewound power resistor, marked 0.25 ohm. It looks like a 25W tubular ceramic. I'm pretty sure it's the output current sense resistor.I measured it with a 4-wire meter, and it measured 24 ohms. I removed it from the unit, and then it measured 26 ohms. Then I applied some power to it, and it seems to have changed to 0.5 ohms. Freaky.There is no physical damage that I can see. I wouldn't think such a failure would be common. It doesn't run hot.I couldn't find one exactly like that, but I found a different style on Digi-Key, and it's on order. We'll see how it goes.

author: SeanB
author_rank: Super Contributor
timestamp: April 25, 2015, 06:53:22 am
content: Probably has a cracked connection to the internal resistance wire coil. Very common on power resistors after they have had a lot of thermal cycles, though this one with 6W or so of dissipation at most should not have failed, it probably had a manufacturing fault where the crimping operation nearly cut through the wire and this eventually fatigued open, the high resistance being from the last piece still joining the 2 sections of wire.

author: cspearow
author_rank: Newbie
timestamp: May 05, 2015, 04:35:54 pm
content: The power supply is running now.The only problem is that the current meter is off. It reads about 3 A when the output current is 5 A.There are several unmarked trimpots on the board, but frankly, I can't be bothered trying to figure it out with trial-and-error methods, so I closed it up and that's that.$41 out the door (plus some time) for a 200W bench power supply. I can live with that.

author: SingleBitError
author_rank: Newbie
timestamp: January 17, 2017, 05:56:06 pm
content: I recently restored a 4050 that I bought at auction a couple years ago. After having no luck finding a manual online I found one on ebay. Spent more for the manual than the 4050.I finally got around to scanning the manual to PDF. I uploaded the manual to the KO4BB site. Should be out of quarantine soon.

author: bitseeker
author_rank: Super Contributor
timestamp: January 18, 2017, 04:33:36 pm
content: Thanks for uploading that, SingleBitError.Some models are rather obscure, especially when it comes to documentation.
Samsung LE40R71B no backlight - Page 1
Forum section: electronics / repair

author: mij59
author_rank: Frequent Contributor
timestamp: January 18, 2017, 06:47:15 am
content: I am trying to repair a Samsung LE40R71B, the backlight inverter doesn't work.All the supply voltages are present , no bad caps, or solder joints found, got sound and can see a picture when the lcd is lit with a flashlight.On power on the backlight doesn't light up briefly.I have attached the schematic of the power supply board BN44-00134A, the problem is with IC1801 (LX1691A) the outputs AOUT and BOUT remain low.On power up the input ENABLE goes high (5V), but this has no effect on AOUT and BOUT.On the power supply board IC1801 is actually a MSC1691AI, I replaced it with one ordered from e-Bay, but AOUT and BOUT seem to be floating.I've also attached a block diagram of the MSC1691AI, the working is not clear to me, e.g. there is no clock signal on DD_CLK.Google search on the topic without result so far, any input greatly appreciated.
Broken utility power meter? - Page 1
Forum section: electronics / repair

author: justinjja
author_rank: Regular Contributor
timestamp: January 18, 2017, 04:18:08 am
content: I do some bitcoin mining, so I tend to keep a close eye on my power usage.Yesterday night, all of a sudden I started pulling 4x more power than normal:BTW this is not like the heater kicking on or something like that,I already use an absurdly large amount of electricity, for a full house even, let alone a 1 bedroom apartment.My apartment building has 2 utility feeds, looks like all the meters on my feed are reading way to high, but the meters on the other feed are fine.Any idea what is up, I'm not going to fix it myself, just curious.Voltage levels are normal,I have no idea what would cause all the meters to go wrong at once, other than maybe a bad firmware update??EDIT:Bad firmware update actually makes sense, it's like they got Kilowatts mixed up with Amps lol
Clean SMD lcd ribbon cable connector - Page 1
Forum section: electronics / repair

author: mau80
author_rank: Newbie
timestamp: January 21, 2017, 03:29:26 pm
content: Hi to all,I'd like to ask your suggestion on clean two SMD lcd ribbon cable connector.The connectors are a female 80 pin SMD ribbon cable connector mounted on LCD pilot circuit.Some liquid, has been entered inside the two connectors and caused a short circuit between ribbon cable pins; now I'd like to replace the ribbon cables, but I've seen that some pin of the female connector present burned tracks.I've tried to use a contact cleaner and a tiny brush, I've reach the result attached in the pictures.I'm not sure that all pins are still present on female connectors, I am concerned that the short circuit had burned out one pin; so I'd like to try to better clean the connector.Can you suggest me same products or techniques to clean?Thank you very muchMaurizio
Printer - Brother 110 Laserprinter - Page 1
Forum section: electronics / repair

author: anishkgt
author_rank: Frequent Contributor
timestamp: January 16, 2017, 04:39:00 pm
content: Hi All,Am trying to test this board of a Brother Laser printer 1110. Would theheat-ononpin 3switch ON the heating drum, if connected to GND on the board ?

author: Cupcakus
author_rank: Contributor
timestamp: January 17, 2017, 07:49:01 am
content: Without a schematic I'm not sure how helpful I can be, but I've worked on a fair share of laser printers... You can be sure a relay of some sort turns on the fuser filament, is there voltage on heat-on?

author: anishkgt
author_rank: Frequent Contributor
timestamp: January 17, 2017, 07:50:20 am
content: Thank cupcakus! Yes there is it is pin 3Sent from my iPhone using Tapatalk

author: Cupcakus
author_rank: Contributor
timestamp: January 17, 2017, 07:58:49 am
content: Well I'd briefly connect it to ground and if you hear a relay switch you have your answer. Not knowing this printer I would not run it like that for any length of time. Be very careful, high voltage will be present.

author: xavier60
author_rank: Super Contributor
timestamp: January 17, 2017, 09:24:36 am
content: Looks like there is a triac on the live side, and likely to be driven by some sort of opto-coupler. Then I wonder what the relay is for.

author: anishkgt
author_rank: Frequent Contributor
timestamp: January 17, 2017, 09:25:07 am
content: Yea I guess will just quickly connect the relay on pin and heat-ON onSent from my iPhone using Tapatalk

author: anishkgt
author_rank: Frequent Contributor
timestamp: January 17, 2017, 09:35:58 am
content: Yea there is one, am guessing that is controlled by pin 3 shown in the second pic.Sent from my iPhone using Tapatalk

author: xavier60
author_rank: Super Contributor
timestamp: January 17, 2017, 09:43:54 am
content: Voltage must not be applied directly to the LED side of opto-couplers, there needs to be a current setting resistor in series.

author: anishkgt
author_rank: Frequent Contributor
timestamp: January 17, 2017, 09:45:27 am
content: Not sure if the opto has anything to do here. Will have to see how pins 2 and 3 works when connected to GND.Sent from my iPhone using Tapatalk

author: jdraughn
author_rank: Regular Contributor
timestamp: January 17, 2017, 01:27:37 pm
content: I would measure resistance between that pin and gnd, and that pin and logic voltage to see if it's pulled up or pulled down.

author: anishkgt
author_rank: Frequent Contributor
timestamp: January 17, 2017, 04:11:30 pm
content: Would the logic voltage be 5 ?Sent from my iPhone using Tapatalk
Need replacement or equivalent part for NEC uPA61A - Page 1
Forum section: electronics / repair

author: ziplock9000
author_rank: Regular Contributor
timestamp: January 20, 2017, 11:22:30 am
content: I'm trying to fix channel 2 on my scope. I've replaced one component that shorted to -12, which seems to have killed the next componentThe part I need is NEC uPA61A. It's a N-Channel Silicon JFET differential Amplifier. But I can't find any old ones for sale, in fact even getting any reference to it at all is a pain.Here's a link to the datasheet:http://www.datasheetlib.com/datasheet/737497/upa60_nec-electronics.htmlA modern equivalent would be just as good.Help would be very much appreciated.Thanks.

author: amyk
author_rank: Super Contributor
timestamp: January 20, 2017, 12:00:40 pm
content: 2N5196?

author: ziplock9000
author_rank: Regular Contributor
timestamp: January 20, 2017, 02:45:42 pm
content: Quote from: amyk on January 20, 2017, 12:00:40 pmThe questionmark worries me. Also, aren't the pins mirrored?Damn £23!
ZD-937 issue - Page 1
Forum section: electronics / repair

author: floresnico
author_rank: Newbie
timestamp: January 14, 2017, 04:57:23 pm
content: Hello. I have a problem with my ZD-937 welding station. I have a resistance that has completely burned. I want to change it but I do not know its value. Would anyone have a ZD-937 station to give me the value?Thank you for your help.

author: mau80
author_rank: Newbie
timestamp: January 16, 2017, 01:08:46 am
content: Hi,I've attach a picture of my ZD-937, the point that you've marked are connected in short.I've checked the image IMG_20170114_173421 - 2 (Copier).jpg; I've found my board is slightly different from yours.Let me know if I can provide other details to you.Thank you very muchMaurizio

author: mau80
author_rank: Newbie
timestamp: January 16, 2017, 11:19:55 pm
content: I've found this post:https://www.eevblog.com/forum/reviews/review-teardown-star-maplin-(oem)-digital-soldering-station/Attached to Reply #6 there is Operators handbook and circuit diagram.Maurizio
Identify missing component in phone front camera subcircuit - Page 1
Forum section: electronics / repair

author: NeoxSys
author_rank: Newbie
timestamp: January 17, 2017, 03:17:49 pm
content: Hi everybody! I'm trying to identify a missing component from my mobile phone board. The whole phone works properly except from the front camera. The component was lost accidentally when I disassembled the device to replace the display. The phone does not recognise the camera, as if it wasn't conected to the board. Let's have a look:It belongs to the front camera subcircuit. As you can see in the image, it is a tiny SMD component with 4 contacts. I would say it may be a kind of FET but since I don't have the schematics diagram of the phone I'm not really sure. What do you think it could be? What kind of components are likely to be used in the phone camera's circuit?My other option is to disolder the other two components below this one, since they seem identical, and measure them to see what they are. But due to the difficulty this is my last alternative.The phone is a BQ model X5. I haven't found its schematics yet.Thanks for your help.

author: daveshah
author_rank: Unknown
timestamp: January 17, 2017, 03:34:15 pm
content: Looks like it might be some kind of EMI filter on the cameras differential signal lines. If you're willing to take a risk I think you might be able to replace it with two 0R resistors of the correct size - or solder bridges - placed horizontally.Edit - three devices in total makes this possibility even more likely as 2-lane MIPI CSI would be a common choice for a lower resolution front camera; and would have 2 data pairs and a clock pair

author: NeoxSys
author_rank: Newbie
timestamp: January 17, 2017, 03:38:22 pm
content: Quote from: daveshah on January 17, 2017, 03:34:15 pmThanks, I will consider taking the risk if no one comes with a better solution. By the way, in the case you are right, what would be the consequence of not having that filter?Edit -Quote from: daveshah on January 17, 2017, 03:34:15 pmIt is a 5Mpx camera. I have an oscilloscope to make measurements, what do you suggest me to do?

author: daveshah
author_rank: Unknown
timestamp: January 17, 2017, 03:52:35 pm
content: The consquences of not having the filter are slightly increased EMI emissions - unlikely to be a big issue; although I suppose it could reduce GPS/cellular performance. If you want to replace it properly have a look for common mode chokes of the correct size.I don't think an oscilloscope will be that useful, the easiest check to do would be to measure which - if any - pins are shorted or low resistance to each other with a multimeter.
DOD 231 Series II graphic EQ Low output. - Page 1
Forum section: electronics / repair

author: cbgpedalmaker
author_rank: Newbie
timestamp: January 15, 2017, 05:14:36 pm
content: A friend of mine asked if I could repair this for him. It is a two channel graphic equalizer. The problem with it is that there is very little output out of it. I was thinking that maybe one of the gain stages failed, but the thing is that this is happening on both channels and they are completely independent. The only thing that they share is an AC chord and the on/off switch and ground. Voltages seem fine for now. I was thinking that maybe, possibly someone has repaired one of these or something similar before? I guess that it's possible that two identical parts on both channels failed at the same time, but I think that it is highly unlikely. I guess that I am going to make sure that the chassis is grounded better and go from there.
fluke 287 dmm - Page 1
Forum section: electronics / repair

author: subeesh
author_rank: Newbie
timestamp: January 16, 2017, 01:10:32 pm
content: hi all i have fluke 287 dmm .now not measurring Vlotages & current. showing on disply "lead connect correctly".can u helpme repairng this

author: mzacharias
author_rank: Frequent Contributor
timestamp: January 16, 2017, 01:59:12 pm
content: Has the meter been exposed to moisture or other contaminants? If the current jack sensing is triggered it will cause this symptom.
W&G NFA-1 - Page 1
Forum section: electronics / repair

author: schenkmi72
author_rank: Contributor
timestamp: January 16, 2017, 10:04:49 am
content: Recently I got a defect Wandel & Goltermann NFA-1 audio analyzer (http://www.amplifier.cd/Test_Equipment/other/NFA-1/Teil1/NFA-1_Teil1.html).I'm searching now for some service manual and schematics (no problem when they are written in german). Are there any NFA-1 owners here ?CheersMichael

author: schenkmi72
author_rank: Contributor
timestamp: January 16, 2017, 11:45:09 am
content: Hi friends,i've attached a picture of the build in self test. The tests BN-959-J, -W and -AC fail. Eventually only the BN-959-J is the essential one.For sure I have a lot more pictures of this beast.CheersMichael
Dick Smith T-2000 soldering station - Page 1
Forum section: electronics / repair

author: Saronni
author_rank: Contributor
timestamp: January 15, 2017, 06:49:13 am
content: My Dick Smith T-2000 soldering station must be about 30 years old now. Over the last couple of years it developed an intermittent problem where the temperature meter would dive to zero and the heater would switch on keep heating without switching off. Wiggling the cable into the handpiece temporarily fixed the problem.Today the problem got so bad that I had to do something about it.I figured the problem was a frayed or broken wire interrupting the temperature sensing circuit so I cut off about 10cm of cable at the handpiece end and re-attached. Problem solved! Checking the removed wires however didn't show any obvious breaks etc so perhaps it was a bad solder joint in the handpiece and it was the re-soldering that actually fixed it?

author: Saronni
author_rank: Contributor
timestamp: January 16, 2017, 09:13:45 am
content: Thanks Wilfred, that will come in handy. I see there's an Australian seller on eBay who has spare tips listed that look suspiciously like those in your XYtronic link (http://www.ebay.com.au/usr/carmates?_trksid=p2047675.l2559).
Verifying an old Philips PM2451 AC voltmeter ? - Page 1
Forum section: electronics / repair

author: alayn91
author_rank: Newbie
timestamp: January 14, 2017, 03:23:43 pm
content: Hello,I bought this voltmeter and I'd like to repair it, if necessary, and make some kind of calibration.To do that, I'd like to find the service manual with the schematics and the calibration procedure.I can only find the schematics on internet.Thank's in advance for your help.Alain.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 14, 2017, 04:08:52 pm
content: Welcome to the forum,The schematics can be found here:http://www.radiomuseum.org/r/philips_ac_mv_meter_pm2451pm_245.html#b

author: alayn91
author_rank: Newbie
timestamp: January 15, 2017, 09:46:27 am
content: Hello,Thank you, I already found it.Now, I'd like to find the full service manual with calibration procedure.I'm ready to pay for it the right price, of course.

author: Gyro
author_rank: Super Contributor
timestamp: January 15, 2017, 10:48:33 am
content: You could start by giving more details of what the fault symptoms are here if you can't diagnose it from the schematic yourself. It's most likely a component failure (possibly PSU?). Don't start tweaking calibration pots yet, it's quite possible that it will already work to reasonable accuracy after repair.

author: alayn91
author_rank: Newbie
timestamp: January 15, 2017, 06:32:52 pm
content: Hello,I didn't yet power it.I will do that tomorow.I will keep you inform.