hybridfree/eevblog-posts huggingface dataset:
Ono Sokki CF-350, not sampling - Page 1
Forum section: electronics / repair

author: Clueless
author_rank: Contributor
timestamp: March 27, 2017, 11:27:22 pm
content: Ono Sokki CF-350 ( says CF-360 when powered up )Unit was working nicely when last used about 2 yrs ago. Now it powers on without obvious error, but does not sample. Cannot get it to accept an external trigger either. The buttons are working and one can navigate the menus but it just won't acquire any data and display it. The battery is fine and the unit had not lost the date. Nothing obviously wrong inside it either. I did not do a careful inspection but there are no bulging or obviously leaking capacitors in the power supply area, analog circuits have +/- supplies present, and +5/+12 are normal.Anyone with a service manual, schematic, or experience repairing one of these ? If not, anyone need some spare parts ?

author: chihaxinh
author_rank: Regular Contributor
timestamp: March 28, 2017, 04:08:57 am
content: Hi CluelessOno Sokki it's japanese product , very hard to find schematics and service manual , like other brand ( Advantest, Panasonic , Kikusui ..etc ).So you can view in topic :https://www.eevblog.com/forum/repair/ono-sokki-cf350-fft-analyzer-needs-repair/You need checking signal from input to DAC . Repair big bother like Ono Sokki take time . But i think can do it , pcb have alot logic chip and memory ram .I don't like all japanese product it's using resistor 1/8W , through hole pin small can rust in long time ( 10 or 15 years ).

author: Clueless
author_rank: Contributor
timestamp: March 28, 2017, 01:51:47 pm
content: HI chihaxinh,What I learned from that earlier posting was that a service manual does exist, but not much from the specifics of the repair. Although this was a nice instrument, it would make more sense for me to buy a replacement than to attempt troubleshooting it without any technical information or a hint to narrow down the source of the problem.CL

author: drtube
author_rank: Contributor
timestamp: June 12, 2018, 08:28:46 pm
content: Hello Clueless, I sent you a PM a couple of hours ago, please read it. Thanks
SIGLENT SPD3303D WITH SHORTED OUTPUT  - Page 1
Forum section: electronics / repair

author: Cyaltronics
author_rank: Newbie
timestamp: June 04, 2018, 04:23:08 pm
content: Hello everybody,My dear old Siglent SPD3303D bought in 2015 probably took offense by being unused since last year, so it decided to turn both channels 1 and 2 in short circuit (with or without any load). Channel 3 works properly, but when I activate CH 1 and 2 (in all individual, serial or parallel modes) the output led turns red as if it would be in CC mode, output voltage on display goes to zero as well as the physical output voltage on plugs.Did anybody encounter same issue? If yes, did anybody resolve this issue? May I get some help to try to fix it?Thank you very much.

author: tautech
author_rank: Super Contributor
timestamp: June 04, 2018, 10:34:26 pm
content: Welcome to the forum.Please contact Siglent in Hamburg for technical support.info-eu@siglent.comYour unit should still just be in warranty.Please report your outcome.

author: Cyaltronics
author_rank: Newbie
timestamp: June 12, 2018, 09:22:37 pm
content: Thank you @tautech for the hint, I'll try to contact them asap.
Tektronix TDS2014B flash and usb eeprom firmware dump needed.\ - Page 1
Forum section: electronics / repair

author: nz_cyrus
author_rank: Newbie
timestamp: June 10, 2018, 08:54:50 am
content: Hi guysI have Tektronix TDS2014B for some reason wont boot up but if I turn it off and on for few time randomly turns on but i get USB controller failed message. Ive already changed usb controller chip but didn't fix it. I guess that would be software problem. but because USB not working I need dumps to update them by programmer. I will be appreciated if someone can help me with this issue. Thanks
Intertek S003IV0600050 - Unknown IC SOT-25 PB07 - Page 1
Forum section: electronics / repair

author: semiRocket
author_rank: Newbie
timestamp: May 24, 2018, 09:10:59 am
content: Hi,I have a wall adapter Intertek S003IV0600050 that doesn't give any output voltage. By investigation, switching IC seems to be dead (Only 7 ohms between Pin 1 and Pin 2). The only issue is I can't find any information on this IC and possibly a replacement part for it.What I found out by tracing on PCB.Pin 1 - VCCPin 2 - GroundPin 3 - Sense on the output possiblyPin 4 - Emitter of the main switching transistorPin 5 - Base of the main switching transistor

author: Gall
author_rank: Frequent Contributor
timestamp: June 09, 2018, 10:24:22 pm
content: It might be iW1676.
Microlab H-200 audio amplifer no sound (play sound when switching off) - Page 1
Forum section: electronics / repair

author: kateriez
author_rank: Newbie
timestamp: June 09, 2018, 04:33:09 pm
content: My speakers have recently gone bad.The amplifier can be turned on but no sound coming out even with input playing.The weird thing is when I switch it off, the speakers would play the sound for a split second and decay.Anybody has any advice on where to look for for this kind of problem?

author: Jamebonds1
author_rank: Newbie
timestamp: June 09, 2018, 06:08:46 pm
content: It can be bad amplifier, capacitor are worn off, etc. If you don't mind, might I asking how long do you have those? Any more detail?
Service manual for Wavetek model 20  - Page 1
Forum section: electronics / repair

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: March 05, 2015, 10:47:56 pm
content: Wavetek model 20 is a small 2Mhz funtion generator.I can find easily the datasheet on the Web, but not the service manual which I willneed soon.Does anybody know where to find it or eventually post it ?Thanks

author: beowulfenator
author_rank: Contributor
timestamp: June 09, 2018, 08:10:52 am
content: I've been looking for the same service manual and found this page. Then I've actually found the manuals, so let me upload them here.This is where I got the file from:http://bama.edebris.com/manuals/wavetek/20/
analog oscilloscope trace brightness - Page 1
Forum section: electronics / repair

author: Belrmar
author_rank: Regular Contributor
timestamp: June 08, 2018, 10:11:33 am
content: my problem is pretty simple and i just want to know if is normal on analog oscilloscopes. Wen reducing the time constant on my proma od-416 the trace brighness starts going down quite abruptly on the <1uS time constants

author: Ian.M
author_rank: Super Contributor
timestamp: June 08, 2018, 10:26:12 am
content: Your Promax OD-416 only has two timebase setting faster than 1us/div.Once the sweep time becomes comparable to the holdoff time, the duty cycle with which the beam 'paints' the trace decreases sharply. Make sure the holdoff control is set to as near minimum as possible for best brightness.If you use the horizontal pull x10 magnification feature its even worse as that makes the X amp overdrive the deflection plates by a factor of 10, so the duty cycle of the visible portion of the trace is reduced by a factor of 10.
TL866 - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: June 06, 2018, 05:01:02 pm
content: Good evening; I'm having a problem with a TL866 programmer. When I install my PIC16F873A (SOIC28) (new); I have an error code displayed, and I can not do anything; neither read nor program it. The support is new, and the direction of the integrated circuit is correct, as well as its legs that touch the contacts correctly. I attach photos. Do you have an idea?? Thank you for you precious help

author: lionelkjh
author_rank: Frequent Contributor
timestamp: June 06, 2018, 05:01:37 pm
content: the following....

author: giosif
author_rank: Frequent Contributor
timestamp: June 06, 2018, 05:38:37 pm
content: I think that, if you uncheck that "Check ID" option at the bottom of the main MiniPRO app window, it should work.Give it a try.

author: ElektroQuark
author_rank: Unknown
timestamp: June 06, 2018, 06:37:52 pm
content: The ZIF socket of the TL866 is really bad.Try opening and closing it with the lever for some times and try again. It could be a bad contact.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 07, 2018, 02:26:44 am
content: you could upgrade to version 6.71 ?? when i have theses errors i remove the check id, make an dump of the ic 2 or 3 times named differently, and reprogram the chip with 1 of those backup, if it still works okay, the tl866 software may have a bughttp://www.autoelectric.cn/en/tl866_main.html

author: lionelkjh
author_rank: Frequent Contributor
timestamp: June 07, 2018, 07:41:45 am
content: Hello everyone! I managed to program my PC thanks to you! It had to uncheck the box: "check id". One note however: is it normal not to be able to read the programming inside the ic? (all the boxes indicate 0 when reading)?

author: shakalnokturn
author_rank: Super Contributor
timestamp: June 07, 2018, 08:54:00 am
content: I guess the code protection is active.
[Solved] Unknown component/device - Page 1
Forum section: electronics / repair

author: mnt22
author_rank: Contributor
timestamp: June 06, 2018, 01:51:05 pm
content: HiWhat is that component it goes by "EM" on the PCBThanks every one.

author: mnt22
author_rank: Contributor
timestamp: June 06, 2018, 01:55:25 pm
content: ?

author: LateLesley
author_rank: Frequent Contributor
timestamp: June 06, 2018, 02:35:53 pm
content: I have no idea - but on the offchance it puts you on the right track, it looks similar to a ceramic resonator. I just came across a ceramic resonator in an circuit, and was looking for what it was. I hadn't come across them. And it does look a little similar to your component.Good luck in identifying it.https://en.wikipedia.org/wiki/Ceramic_resonatorIt may also be a ceramic filter, I just stumbled across them.https://www.google.co.uk/search?q=electronics+ceramic+filter&num=50&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjs9a_7oL_bAhUJzFMKHbwfDWkQ_AUICygC&biw=1528&bih=850

author: picburner
author_rank: Frequent Contributor
timestamp: June 06, 2018, 04:35:51 pm
content: I think it is a three terminal EMI suppression filter like these:http://www.globalsources.com/gsol/I/EMI-filter/p/sm/1001918177.htm#1001918177

author: Chris56000
author_rank: Frequent Contributor
timestamp: June 06, 2018, 06:05:45 pm
content: Hi!That is indeed what it is - it's a capacitor with an input lead, an output plate and a common, forming a 'T' filter with two ferrite bead supressors, represented like this:-Chris Williams

author: ArthurDent
author_rank: Super Contributor
timestamp: June 07, 2018, 12:49:01 am
content: Yup, EMC filter is correct. Here is a photo of a nearly identical one.
identify ferrite core type please? - Page 1
Forum section: electronics / repair

author: JoanTheSpark
author_rank: Contributor
timestamp: June 16, 2018, 04:30:53 am
content: I came across this ferrite core and was wondering what type it is.Can't seem to find anything via image searches on google.It's a transformer out of a switching power supply.The pins have only been populated on one side, as for the low voltage side they came out lose and made their way to another place on the PCB.Height of overall assembly: 24.6 mm +/- 0.1 mmHeight of a half core thus: 12.3 mmWidth/length of edge (square): 39.2 mm +/- 0.1 mmIt looks a bit like a RM core as it uses similar springs/clamps.Thanks!

author: tautech
author_rank: Super Contributor
timestamp: June 16, 2018, 05:11:22 am
content: You can shift this thread yourself.Bottom left of the page is Shift Topic, click there and just follow your nose.For SMPS it'll be working in the 20-60 KHz region and probably the best way to use it is to work backwards from the PCB in which it was in. Hunt out the datasheet for the controller and you just might see a 'Typical application' that matches your PCB layout. If you're super lucky the schematic might even list suitable cores and wire gauges used.Some little detective work can teach you lots.

author: PKTKS
author_rank: Super Contributor
timestamp: June 16, 2018, 01:49:25 pm
content: I have seen worst than that one.Usually I take apart the enclosure to reach the coreThen I seek all possible ends and do a tight measure on eachWhile tracing a schematics to see if that is just an inductoros some type of complex self inductance or transformerVintage parts will not only be hard to find specs but alsoalmost impossible to find replacementAt that point sometimes you may fix it yourself or not.BE AWARE!! that some ferrite cores crack very very easily.pieces and parts may crack in disassembly procedureMy own experience... they got old and they crack more easilyTake care.Paul

author: TimNJ
author_rank: Super Contributor
timestamp: June 17, 2018, 05:33:51 am
content: Are you sure that’s a transformer? Looks like a PFC choke.It looks a lot like YuJing QP horizontal mount.http://www.yujingtech.com.tw/e-product-05.htmlEdit: Actually it’s almost definitely a YuJing part based on the ‘YJ’ on the label.

author: JoanTheSpark
author_rank: Contributor
timestamp: June 17, 2018, 10:56:07 am
content: Quote from: TimNJ on June 17, 2018, 05:33:51 amYou're right on both accounts.The transformer was a misunderstanding with my dad.It's a choke.Thanks again.
HP 6106A neet recappng as part of repair - Page 1
Forum section: electronics / repair

author: krefior
author_rank: Newbie
timestamp: June 04, 2018, 05:28:57 pm
content: I have quite a few of these old HP/Harrison power supplies of various models from back in the day, They just seem seriously over built tanks. I've even bought several "Untested / Parts only" ones that still work wellLast year I picked up an HP6106A 0-100V for parts, and it does not have any output, I've got the operators / service manual and will begin troubleshooting when I get a little free time, but want to see what the hive mind thinks about the need for complete recapping is. My first instinct is just to repair it, but my other project that in queue for is to bring my Tek 2445A back into spec, and that really is a recapping project, got me to wondering if I should just order caps for both projects at the same time...

author: tkamiya
author_rank: Super Contributor
timestamp: June 04, 2018, 05:42:28 pm
content: My basic philosophy on repair is, "do no harm". If I see a bulging, leaky, or otherwise damaged capacitor, I'll go ahead and replace it. I might replace a few more in the same circuit and near by. But I do not replace every capacitor just because. I know what manufacturer says about diminishing capacitance, but keep in mind, most caps are +100% and -20% tolerance. In other words, they are over-spec'd.

author: GerryBags
author_rank: Frequent Contributor
timestamp: June 04, 2018, 05:59:43 pm
content: Quote from: tkamiya on June 04, 2018, 05:42:28 pmI thought that figure refers to the criticality of the capacitance value to the use in the circuit, i.e.: what value can be used as replacement, rather than anything related to the part itself.

author: krefior
author_rank: Newbie
timestamp: June 05, 2018, 03:08:29 pm
content: tkamiya - That's in line with how I usually do repairs - the more you replace, the more you risk stumbling onto something that is critical... And of course even if the unit has double it's spec'd ripple or 1-2% less regulation, it'll still be fine for what I'm doing!

author: tkamiya
author_rank: Super Contributor
timestamp: June 05, 2018, 04:51:15 pm
content: Gerry,That figure comes from a spec sheet I read long time ago. It refers to the difference between actual value and spec value of electrytic capacitors. I may have changed but that's what I recall. Being 80s and I was in Japan at that time, it was probably either Nichicon or Panasonic.
Repairing power supply unit of Philips PM 3065 CRO - Page 1
Forum section: electronics / repair

author: afsar
author_rank: Newbie
timestamp: June 04, 2018, 05:36:56 pm
content: Hi everyone,I want to repair power supply unit of Philips PM 3065CRO of the late 80s. That is my first repair. Please suggest me tips and safety issues. Can multimeter be sufficient to test and repair power supply unit as it has HT voltage? Please help!

author: jancumps
author_rank: Unknown
timestamp: June 04, 2018, 08:29:19 pm
content: my bet is that the largest electrolytical capacitor failed and took out the rectifier. a typical failure these days for 80s and 90s Philips scopes.

author: cheeseit
author_rank: Regular Contributor
timestamp: June 04, 2018, 09:00:07 pm
content: You should have kept this in the previous thread you started but maybe a mod can merge them.I'd suggest that you just replace most capacitors without measuring anything, especially while the scope is powered up, but only attempt this repair if you honestly feel confident that you can do this safely. This kind of repair can easily kill you - keep that in mind at all times. Otherwise get someone capable of doing it to help you, or pay someone to do it. Remember that both the CRT tube and components on the PSU board can kill, and not just by electrocution. Your life is worth a heck of a lot more than a scope repair, and being dead just sucks.Readthisandthis, and make sure you understand everything before you proceed. Perform further research (Google) if you're the least unsure, or just stop here. If you feel up to it then discharge the CRT safely.Follow the disassembly procedure in theservice manual(wait ~30 seconds for the "...Processing..." to change to a "Get Manual" download link), making sure only to touch the board by the edges and discharge the capacitorssafely, especially the two large ones behind the power switch. Perform further research (Google) if you're the least unsure.The reason I suggested checking and replacing electrolytic capacitors in your original thread is that the whistling/whine is most likely caused by the transformer being strained by bad/out of spec caps. This is apparently a common problem on this series of scopes, and I repaired a similar scope with the same problem recently. I replaced all electrolytics except for C6007, C6008, C6100 and C6101 that were fine. Almost all the smaller ones were way out of spec and I'd suggest that you start by replacing those first.Keep in mind that several versions of this PSU were used but they are generally more or less like the one in the SM linked above. Replace caps with same voltage rating and capacity, preferably 105° degree, and don't use super low ESR types. You should also replace the golden resin encased RIFA caps if found since they have a strong tendency to blow up.You didn't specify if the scope works, apart from the noise, so this may or may not be all that you need to do to repair it but it's certainly a good start.
CHASE HFR2000 Interference Measuring Receiver Manuals ? - Page 1
Forum section: electronics / repair

author: chris_leyson
author_rank: Super Contributor
timestamp: June 04, 2018, 08:48:07 pm
content: Just rescued a CHASE HFR2000 EMC measuring receiver from landfill. Does anybody have a copy of the operating manual or better still a service manual. I don't think CHASE published a service manual so I might be out of luck there. It's 1985 vintage and blows fuses, probably a shorted tant, there are eight of then in the power supply.I was keen to get into the RF section and have a good look, the top half of the RF section might be a doubly tuned bandpass filter and I think the bottom half of the RF section might be the local oscillator. Can't see any sign of a mixer anywhere or a detector for that matter. Anyway, fix the power supply first.

author: chris_leyson
author_rank: Super Contributor
timestamp: June 04, 2018, 08:49:14 pm
content: RF setion top half.

author: chris_leyson
author_rank: Super Contributor
timestamp: June 04, 2018, 08:50:26 pm
content: And I guess this has to be the IF section. IC401 is SL612.
KA3005P Display Error - Page 1
Forum section: electronics / repair

author: DD1VD
author_rank: Newbie
timestamp: April 25, 2018, 03:01:54 pm
content: Hello,I hope you can help.After reading about the KA3005P and the amazing story concerning the hardware fix done by KORAD I bought 2 power supplies.One of them worked without any issues until today.If I switch on the PS I can see the display readout like in the attached picture.I checked and cleared all the connections between the main display board and the display unit in the front.After that it worked for 5 mins and then failed again.Any hints, tips, solutions?Thank you very much.Regards,Andy73 de DD1VD

author: DD1VD
author_rank: Newbie
timestamp: April 25, 2018, 04:16:56 pm
content: Hello,I just forgot to add the PS is working fine beside the display issue.If you setup voltage (you have to guess a little bit) and current and press OUT everything is ok.Regards,Andy

author: mikerj
author_rank: Super Contributor
timestamp: April 25, 2018, 04:48:23 pm
content: Since disturbing it made it work briefly, I'd suspect a bad solder joint on the display board. Try applying pressure to the PCB with something insulated (e.g. a plastic pen, screwdriver handle etc.) whilst the unit is operating to see if you can narrow it down.

author: DD1VD
author_rank: Newbie
timestamp: April 26, 2018, 12:22:19 pm
content: Hello,Thanks for the suggestion. I checked all the PCB in the front of the device including the re-soldering of the connections between the main board and the display board. No changes. I assume that something in the path for the voltage selection is broken. Current can be set without any issues.Regards,Andy

author: Biker61
author_rank: Newbie
timestamp: June 04, 2018, 06:17:49 pm
content: I have the same problem.It came up when i tried to calibrate the PS via the M4 button.It also seems that the PS is now in the wrong version mode (15Volt Device)Has anyone instructions how to calibrate propperly orhow to set corret version/mode orhow to reset to factory settings?

author: HoracioDos
author_rank: Frequent Contributor
timestamp: June 04, 2018, 06:30:59 pm
content: Quote from: Biker61 on June 04, 2018, 06:17:49 pmHere it goes.

author: Biker61
author_rank: Newbie
timestamp: June 04, 2018, 06:51:43 pm
content: Many thanks for the swift document link!I already had this information from an other post.Unfortunately this procedure is outdated and the mentioned M1 button is no longer responsiveI guess the M4 has to be pressed instead but this is risky! KEEP away from this calibration stuff !!!I ended up with totally messing up the settings in the KA3005P.And i have no idea how to get this fixed.Any help is appreciated.

author: HoracioDos
author_rank: Frequent Contributor
timestamp: June 04, 2018, 07:41:00 pm
content: Quote from: Biker61 on June 04, 2018, 06:51:43 pmYou might try to contact their support. They used to have a user in this forum.krissy@koradtechnology.com
Yamaha RX V465 turns of after few seconds - Page 1
Forum section: electronics / repair

author: hemant_2222
author_rank: Newbie
timestamp: June 04, 2018, 06:11:29 am
content: Hi All,This is my second unit that i have taken for repair.The first one was also yamaha and was repaired with help of Mark, Z ( if i am not wrong )Now, coming to this unit,The first place i checked was for the DC offset at the output and there is approx. 2.5 to 5.0 volts at the middle pin of emitter resistor.Also, the supply to both the STKs are +/- 24 volts instead of +/- 50v, as per the schematic. Is this the place to start with.Please assist.Regards,Hemant.
Tektronix 556 and 565 restauration - Page 1
Forum section: electronics / repair

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: June 01, 2018, 07:17:14 pm
content: Hey everyone, yesterday I picked up a 556 and a 565 for 150€ each, including an 3A5, 3A7, 1A2 and 1A4 plugin. Today I tried both and noticed the following obvious problems:556right plugin slot doesn't respondleft plugin: the horizontal position only pushes the traces a few millimeters aroundswitching the plugins doesn't move the error to the other sidefocusing isn't exactly the bestthat darkened mesh inside the front bezel is loose. Any suggestions on how to glue that back on?Many of those small plastik knobs from the toggle switches are missing565traces doesn't show up at all, but dots are briefly visible while heating up - so at least the tube and HV are working kind ofI guess I will start with the 556 since it at least displays something which could help in finding faults.I will post high res pictures as I go on working at those and keep you updated if there is someone interestedAny Ideas, comments and so on are always appreciated.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 01, 2018, 10:44:39 pm
content: https://groups.io/g/TekScopes

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: June 03, 2018, 04:48:58 pm
content: Thanks for the link, but I have to admit that I don't really understand those newsgroup style forums, so I think I won't be too happy around there.However, I started with the 556. I started with some hours of cleaning work. That wasn't too bad since the scope has lots of room to go around with the brush, cotton swabs and window cleaner.The plugins were cleaned under running water and being dried in the sun right now. Since I wasn't all to thrilled to disassemble the transformers from the main unit I decided to clean many things inside just with a dry brush or cloth - which worked very well. Also I glued the mesh from the front bezel back on, removed the crumbly dust which was once an air filter and lubricated moving parts as suggested by Tektronix in their lubrication manual.While cleaning I also noticed a fault that will definitely influence the missing lower beam: The 6GF5 Compactron Tube is broken, so no wonder that there is no beam available.Also I found some sprague paper caps which should be leaking by now, which could be a reason for the focus and position problems I encountered. We will see when spares arriveI have attached some more photos to enjoy taking a look at this wonderful device.

author: GerryBags
author_rank: Frequent Contributor
timestamp: June 03, 2018, 05:28:59 pm
content: That looks in pretty good condition, at least like it was stored in the dry. Looking forward to watching your progress. I'd love to have one of these in my lab, beautiful machines!

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 03, 2018, 09:54:10 pm
content: 3A5? I'm very envious!
Best IC socket? - Page 1
Forum section: electronics / repair

author: Skyfox
author_rank: Regular Contributor
timestamp: June 01, 2018, 09:08:37 pm
content: When installing an IC socket, what type is best for long term reliability and good connection: the machine tooled kind with the post pins or the dual wiper type with the flat pins?

author: bsudbrink
author_rank: Frequent Contributor
timestamp: June 01, 2018, 09:09:28 pm
content: Machine turned by far.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 02, 2018, 02:37:45 am
content: by experience machine tooled, but the insertion force is greater, care must be taken like: very straight pins or no solder blob/excedent on them (clean them with solder wick)

author: james_s
author_rank: Super Contributor
timestamp: June 02, 2018, 05:48:50 am
content: The machined pin type are dramatically superior, they're a lot more expensive though so it isn't always worth it.

author: bd139
author_rank: Super Contributor
timestamp: June 02, 2018, 07:57:24 am
content: Harwin and amp turned pin sockets are good. You do need a leg straightener tool if you’re socketing ICs as well as good sockets.Don’t buy no brand sockets, even turned pin. They are terrible.Also don’t expect any IC socket to last more than a few insertions. If you need to do that, use a ZIF socket.Really though the best socket is no socket!

author: james_s
author_rank: Super Contributor
timestamp: June 02, 2018, 06:39:56 pm
content: I generally only use sockets on programmable parts, and stuff like drivers that are exposed to the outside world and may be damaged. Otherwise I've had problems caused by sockets almost as often as I've had problems caused by bad ICs.Can't say I've ever had a bad machine pin socket though.

author: tkamiya
author_rank: Super Contributor
timestamp: June 03, 2018, 06:35:19 am
content: I've seen both types fail. The machine type tends to collect dust and moisture. The cheaper type works fine for decades until it decides to quit.The machine types tolerate plugging/unplugging cycle better than cheaper type. The cheaper type can wick solder into contact area, depending on design.Really, if reliability is an issue, I'd not use any socket. When socketed boards fail, first thing everyone tries is unplug and plug every socket. That should tell you something.

author: jfphp
author_rank: Regular Contributor
timestamp: June 03, 2018, 09:57:06 am
content: The machine tooleddoesn't like vibrationsdesoldered IC ; they open the contacts and a new IC is less fastenedis prone to oxidation : putting out an in the IC is not as efficient as with the cheaper support.As explained best solution is no support (except for ROM, RAM, processor,...) : old Tek stuff was full of supports including transistors and restart is a nightmare.

author: dacman
author_rank: Frequent Contributor
timestamp: June 03, 2018, 07:53:55 pm
content: I've had several IC pins break off when trying to remove them from a machined socket. I prefer gold-plated sockets.
Cleaning old oscilloscope rotatory switches - Page 1
Forum section: electronics / repair

author: Belrmar
author_rank: Regular Contributor
timestamp: June 03, 2018, 11:19:42 am
content: Well i got an old promax od-416, it had some faults but most of them are fixed . now i am vaving some problems with the rotatory switches . sometimes they dont make a correct contact and the offset and time constant goes crazy, turning the switch a few times fixes it, but not as ideal as i would like it to be

author: Harb
author_rank: Regular Contributor
timestamp: June 03, 2018, 11:25:59 am
content: Deoxit.......works a treat, spray it on the contacts and twist the knob a few time and 9 out of imes its fixed

author: rhb
author_rank: Super Contributor
timestamp: June 03, 2018, 07:15:20 pm
content: Much safer to soak a piece of bond paper in Deoxit and pull that through the switch contacts..Do NOT spray cleaner around the input attenuator section unless your intent is to destroy the scope. Tek warns about this in their service manuals for the 465 et al. It's apparently very bad for the capacitors.
How to start a DS1500-3 Astec  server PSU  - Page 1
Forum section: electronics / repair

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: June 03, 2018, 01:50:33 pm
content: Hi All,I have a DS1500-3 Astec server PSU that I want to start. It should be able to provide 123 A on 12V.I found the doc ( attached).When I power the unit, the fan goes on, and the green light is blinking. This is normal.But not I need to start it really.I have connected the B3 (PSON) to GND, but this was not enough to make it go ( none of the other pins were connected).Does someone has any hint ?ThanksThis is what is in the doc :Logic ControlPS_ONAn active low signal that turns on the 12vdc power rail. When this signalHigh, or left open, the 12vdc output turn off. The 3.3Vsb output remains on.POKIs a power good signal to be pulled low by the power supply to indicate thatall the outputs are within regulation limits of the power supply. (turn-ondelay 100 - 500mS)PS FAILIn the event of a power supply failure (OVP at any output, UV at any output,OTP or other electrical failure), this signal shall go to a High state.AC OKHigh when AC is not OK, Low if AC is OKPRESENTLow i f PSU is Present, High if not Present; Pull high in system.FAN FAILLow if one or both fans have failedPS_KILLThis pin shall quickly turn off the power supply and prevent arching ofthe DC output contacts

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: June 03, 2018, 02:30:20 pm
content: With some additional search on the web, I solved my problemhttps://www.xsimulator.net/community/threads/how-to-modify-a-server-power-supply-for-12v.5774/To start the unit, one has to put bothB3 (PSON ) and B4 (PSKILL) to GND ( A2,B2,C2,D2).I put B4 to GND, and a switch from B3 to GND. Everything seems now to be OK.
HP E4433B SRAM failure again? - Page 1
Forum section: electronics / repair

author: Oldtestgear
author_rank: Regular Contributor
timestamp: June 02, 2018, 04:36:54 pm
content: I have 2 of these showing the same fault. According to the service guide the LEDs are showing that the BOOTROM RAM test has failed. It powers on but does not get past this point. It seems that there are 2 RAM chips fitted & I am guessing that the HM628512 is the likely culprit. Has anyone ha experience of this failure mode & able to offer any guidance or am I just plain unlucky. I also have a 3rd one that may have the AWG SRAM failure as well. Ironically the 4th one I bought has a dead RF output but at least there is a bit more information on this one.Any thoughts appreciated.Phil
Anyone familiar with salt water chlorinators? - Page 1
Forum section: electronics / repair

author: e100
author_rank: Frequent Contributor
timestamp: June 02, 2018, 07:27:06 am
content: I'm seeing some strange voltage and current readings.I believe that my unit consists of a mains fed triac which runs into the primary side of an isolation transformer. The low voltage output winding is centre tapped, and goes to the chlorinator +ve electrode. The -ve electrode return wire splits and goes to two thyristors that return to the current to the two transformer ends.The thyristors provide rectification and are also used as gas detection switches by running the gate wires to the void above the chlorinator. When filled with water, current travels from the chlorinator +ve electrode through the water and to the gates.Measuring the voltage across the chlorinator electrodes, at the triac minimum setting it looks pretty normal although there is a small bump on the left.I speculate that the 3v offset is due to the chlorinator electrodes behaving as a battery (is this correct?).As I turn the triac dial, the bump on the left gets bigger and doesn't look like any pictures I can find on the web.The current waveform tracks the voltage waveform and goes to zero at the 3v threshold. The peak current is about 15 amps. The bump is delivering current.Picture belowDoes anyone understand what's going on?

author: tautech
author_rank: Super Contributor
timestamp: June 02, 2018, 10:57:29 am
content: Looking at the screenshots and the frequency reported as 100Hz it's 2x your line frequency plus we see the amplitude increasing as the Triac ON time is longer. Longer ON time = higher amplitude = higher current.I'm guessing the Triac ON time is controlled by phase control, that is some time after zero crossing of the AC for minimum current to shortly after zero crossing for max current.

author: e100
author_rank: Frequent Contributor
timestamp: June 02, 2018, 02:32:54 pm
content: I should of posted this earlier, here's a drawing showing what I'm asking about. What's the little bump to the left of the main thyristor trigger point?(The mains frequency is 50Hz)
What is this device marked VR1? - Page 1
Forum section: electronics / repair

author: semiRocket
author_rank: Newbie
timestamp: June 02, 2018, 07:53:27 pm
content: Hi,Found this inside a DSL splitter between line wires, seems like some kind of suppressor device, anyone knows exactly what it is?There are no markings on it.

author: semiRocket
author_rank: Newbie
timestamp: June 02, 2018, 09:04:22 pm
content: Or this device marked as 'G'. Gas discharge tube?

author: chipwitch
author_rank: Frequent Contributor
timestamp: June 02, 2018, 09:17:41 pm
content: I assume by "gas discharge tube" they're referring to a method of lightning/surge suppression, but I could be wrong.

author: nanofrog
author_rank: Super Contributor
timestamp: June 02, 2018, 09:40:30 pm
content: VR typically refers to a variable resistor (or varistor). 2 leads usually indicates a rheostat, but in this case, I think a MOV (metal oxide varistor) is the actual part being used. They're more commonly a disk shape with parallel leads, they may have located an axial version to fit the enclosure.And given the photo of the second photo, I'd say it's a gas discharge tube.

author: metrologist
author_rank: Super Contributor
timestamp: June 02, 2018, 09:46:19 pm
content: I've seen VR used for voltage regulators too. I wonder if it is a zenor diode?

author: helius
author_rank: Super Contributor
timestamp: June 02, 2018, 09:53:28 pm
content: Considering the placement between pins of a twisted-pair, I would bet it's a TVS. TVS is effectively two back-to-back zeners, so I suppose the symbol makes sense.
Philips PM 3065 Oscilloscope repair help - Page 1
Forum section: electronics / repair

author: afsar
author_rank: Newbie
timestamp: June 02, 2018, 08:30:04 pm
content: Hello guys,After a long struggle, I got Philips PM 3065 old CRO to test my circuit but unfortunately, it is not working. I tried to fix it but as a beginner, I could not find it where to start fixing. I had open the case and found power supply was making the whistling sound. As a new one is too costly for me so please help me.

author: cheeseit
author_rank: Regular Contributor
timestamp: June 02, 2018, 11:50:59 pm
content: Check the electrolytic capacitors on the PSU board, some or most are likely bad with high ESR and/or are low capacity.

author: Shock
author_rank: Super Contributor
timestamp: June 05, 2018, 08:46:58 am
content: Measure the capacitance and ESR on the secondary filter caps and replace if needed.Replace the Rifa X2 if it's an original, bound to catch on fire eventually.
Sennheiser K6 mic power module schematic - Page 1
Forum section: electronics / repair

author: peteb2
author_rank: Regular Contributor
timestamp: May 31, 2018, 10:24:41 pm
content: After trying two downloadable "Service Manuals" websites and parting way with the princely amount of USD$5 each time for the unit's service manual but ending up with what is the operator's instruction set, does anyone have the page with the schematic please?I am trying to help out a chap whose hobby of making wedding videos has seen his K6-M6 shotgun mic to have developed a nasty random crackle even though i have tried tightening the 'earthing' screw in the body. I think one of the pins in the socket has cracked the solder off the circuit board...

author: floobydust
author_rank: Super Contributor
timestamp: May 31, 2018, 10:45:58 pm
content: Usually it's dirt, spit, lint etc in the capsule or a cracked solder joint.Is it on battery or 48V phantom power it crackles?Found this schematic.

author: The Soulman
author_rank: Super Contributor
timestamp: May 31, 2018, 10:49:01 pm
content: It is not a very advanced device so repairing it without a schematic shouldn't be to difficult, especially if it's a bad contact/solder joint as you mention.Also make sure the battery contacts are clean and tight.Good luck.

author: peteb2
author_rank: Regular Contributor
timestamp: June 01, 2018, 02:26:13 am
content: Awesomely indebted guys.... There's one obvious pin where the XLR cable goes in that wobbles a lot more than the others so i bet it's cracked the solder to the board ... or the flexi-loom by the looks. We'll work through pulling it apart and see what gives.... Interesting circuit. I never knew mics could be made so they're so dang complex!
Lambda LQ-534 Benchtop Power Supply Repair - Page 1
Forum section: electronics / repair

author: snerp
author_rank: Newbie
timestamp: June 01, 2018, 12:13:23 am
content: I'm trying to get a LQ-534 up to snuff for Titanium Anodizing. I downloaded lq530.pdf and started going through the "Complete Power Supply Calibration Procedure". It appears R111 and R104 have been messed with since there was no adhesive present on either potentiometer. When attempting to adjust the pot, I am getting nothing on the built in display or my ampmeter.Before I attempted the procedure, I was getting a reading on the display, but it was reading low at maximum. Should have probably checked with my ampmeter to see what it was at, but since I was planning on going through the whole procedure anyways I didn't think. I am still getting voltage readings though.Are the pots toast or is something else wrong here? I didn't let any smoke out, so that's a good thing.Any help is much appreciated.
VICTOR 6056B CLAMP METER SCHEMATIC anyone ? - Page 1
Forum section: electronics / repair

author: PKTKS
author_rank: Super Contributor
timestamp: May 26, 2018, 01:37:07 pm
content: Hello folks.Yet another crappy TANTALUM CAPACITOR should have gone wild.This time there is no "exploded" or black CAP to make things easy.Schematic will help a lot if any available or even partial BAT INPUTThanks a lot in advance any helpPaul

author: PKTKS
author_rank: Super Contributor
timestamp: May 28, 2018, 02:29:46 pm
content: OK folks.. cheapos are hard to find parts and specs.Here is the thing dismantled.COB on board and some chips hard to find any referencePaul

author: PKTKS
author_rank: Super Contributor
timestamp: May 28, 2018, 02:31:56 pm
content: It was "DEAD" with some HOT AREA near a SOT23 packagemarked V1PH which by the way I found absolute nothing about ...Judging the marked resistors and huge CAP that may be an LDOBy HOT I mean HOT.

author: PKTKS
author_rank: Super Contributor
timestamp: May 28, 2018, 02:34:55 pm
content: After testing the huge 220uF 16V CAP and the transistors near byand a reflow of that area..The thing turns on but not properly.The V1PH chip has gone from nothing (VERY HOT) to around 3Vwhich i have no clue if it is the proper output.At least it is not hot anymore. But the reflow was not enough

author: PKTKS
author_rank: Super Contributor
timestamp: May 28, 2018, 02:40:33 pm
content: If anyone has any clue about that V1PH chipplease post some reference.It may help to find a suitable replacement.Also that chip marked TI 68 i333 does not fit anything anywhere.The rest is more or less easy to findPaul

author: PKTKS
author_rank: Super Contributor
timestamp: May 31, 2018, 03:44:31 pm
content: For the record:- the thing is a cheapo - but for the money if you ask - it is OK- problem is: if you sum a cheap but solid design WITH LEAD FREE SOLDER...- what do you get? a CRAPPY LEAD FREE SOLDER cheapo.- several lead free solder joints were just CRAP. I mean CRAP.After reflow some other joints and arranging the ROTARY SWITCHwhich is not all that solid good...The thing is working properly. Even that V1PH which BTW is indeed a 3.3V LDOSummary:- For 30/35 U$ an AC/DC CLAMP capable of 1000Amps is bargain- Even if you have to reflow some crappy parts of the cheap crappy LEAD-FREE PCBIt is solid - it has no internal fuse (assumed that all job is in the clamp)- protection is left to the MOV and PTCwith BONUS of a relative OK TrueRMS voltmeter and the usual DMM goodiesBARGAIN.If you need a 1000A AC/DC clamp costing just U$30 box - it may be worthyPaul
Kikusui COR5541U oscilloscope readout off screen - Page 1
Forum section: electronics / repair

author: JanR
author_rank: Newbie
timestamp: May 31, 2018, 07:42:02 pm
content: Hello!I've been following Eevblog for quite some time and now I finally joined the forum!I recently bought a Kikusui COR5541U analog/digital oscilloscope from the early 90s. The analog traces work perfectly, but after using it a while the digital cursors and readouts started moving downwards and out of the screen. Now when the scope is powered on, the last row of numbers is partly out of the screen. After a while it goes even further. Of course when the scope is in digital mode, the trace also moves out of screen. Sometimes everything on the screen disappears, but returns when restarting the scope.What can be the cause of this? Bad capacitors? I have tried to find a service manual online but with no luck. There are many trimmers inside the scope, but I'm afraid to touch anything, since the problem is not constant.Thanks in advance,Jan

author: SMdude
author_rank: Frequent Contributor
timestamp: May 31, 2018, 10:08:53 pm
content: I don't have a manual, but the first thing I would do, given that it is (was)ok when cold, but no good after "warming up" would be to carefully warm (hot air solder station is ideal)around the board(with everything cold) and see which area you hit to cause it to show the problem.From there you can probably narrow it down.A can of freeze spray may be handy too.Don't let the scope bite you!I'd be looking at any electro's in the suspect area first.Good luck!If the above doesn't do anything for you then a schematic will be the best help.

author: JanR
author_rank: Newbie
timestamp: June 01, 2018, 03:47:10 pm
content: Thank you. Heating with a hot air station is a good idea. I'll try that.I also contacted Kikusui and they were kind enough to send the service manual.I'll keep you updated on the progress.
Philips SBC830 Multimeter Repair - Page 1
Forum section: electronics / repair

author: belzrebuth
author_rank: Frequent Contributor
timestamp: May 29, 2018, 01:45:18 pm
content: I can't find any info about it on the net.The multimeter turns on and seems to recognize the different ranges when I turn the selector in but I get no readings..No resistance readings, no voltage reading, no continuity...the only thing that seems to work is the current measurement and only on the unfused 20A terminal..I've tested only up to 1A and the meter seems to track the current.It's pretty clean inside no dust, corrosion or battery leak of any sort..Also, the 360mA fuse is replaced with a 3A.I've already cleaned the pcb tracks of the mode selector.Where should I start troubleshooting this?

author: belzrebuth
author_rank: Frequent Contributor
timestamp: May 29, 2018, 01:46:33 pm
content: I probably did something wong when uploading those images...

author: Chriss
author_rank: Frequent Contributor
timestamp: May 29, 2018, 01:50:26 pm
content: I would check for first if there is somewhere some shorted componenet.Then I would check every ic for some problems.After all this I would start to check if the values of the componenets are in good range...Sent from my GT-I8260 using Tapatalk

author: shakalnokturn
author_rank: Super Contributor
timestamp: May 29, 2018, 11:50:05 pm
content: I'd start getting the rotary switch off, checking the state of contacts under there and cleaning them. (Also make sure the contacts are all there and in the right positions.)Then the state of the trimpot (does it still have a track and brush after all the bashing it has taken?), then figure if that BD435 is there to regulate anything, then find the datasheet for whatever hides under the LCD. (Intersil ICL something?)By then you should be well on the way.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 31, 2018, 09:02:59 am
content: seems to be based on ICL7106 ICL7107 chips ?? you can find schematics who could help

author: mzacharias
author_rank: Frequent Contributor
timestamp: June 01, 2018, 04:19:29 pm
content: To start with I would take another multimeter and confirm approximately 10 to 11 megohms input resistance from the test leads through the Philip's input jacks.