hybridfree/eevblog-posts huggingface dataset:
Sencore LC-102  Locks up on "open" test - Page 1
Forum section: electronics / repair

author: Bargainhunter
author_rank: Regular Contributor
timestamp: May 02, 2025, 06:40:56 pm
content: I was calibrating my Sencore Lc-102.After adjusting the voltages to specs, I went to calibrate the capacitor values.The "Short" leads test works okay but when I open the leads and press "Open" the LC-102 locks up.Any suggestions as to what is wrong?Thank you.

author: floobydust
author_rank: Super Contributor
timestamp: May 02, 2025, 07:44:58 pm
content: Check DC-DC converter making +/-5VDC rails, it might be overloaded due to a bad IC. As discussedhere.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 02, 2025, 08:50:26 pm
content: do you have the original sencore tests leads

author: Bargainhunter
author_rank: Regular Contributor
timestamp: May 02, 2025, 09:07:44 pm
content: I don't have the original Sencore test leads but it locks up without any leads attached when I press the "openn" test switch.The display shows one dash and the unit locks up. I have to turn it off and back on again to unlock it.I do have all voltages present including +5 and -5.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 03, 2025, 01:31:03 am
content: thoses lcr absolutely need a specific cable made with rg62a or b, the cable has specific capacitance, at least 13 pf per feet, no other can substitute it, one guy is selling DIY ones on ebayand yes it can affect the open / close testas for not putting any cable and do some teststhoses lcr's are prone to big relay failure, relay contact oxydation, the Cornell Dubillier one is to check ...some micro relays may have problems tooeven if you did some voltages calibrations in it, you surely found out the schematics and how to's ... you need the specified parts for the tests, maybe some lythics caps may have began to be less efficientthis instrument is sensitive, and not too hard to service BUT you need to do the right procedures and checks, not changing parts for nothingthe previous thread links of the repairs are somewhat good and not, the guy ended up by abandoning the repairthere was talk about a diode in the circuit who can play tricks, leads wires etc ... relay(s)https://antiqueradios.com/forums/viewtopic.php?t=383930https://www.eevblog.com/forum/testgear/wtb-sencore-lc102-capacitor-inductor-analyzer/msg2584998/#msg2584998you do have the error 7 who can happenand you have many lc102 103 threads here, or on the web
Sencore lc 102 repair Need tech. - Page 1
Forum section: electronics / repair

author: Drjaybee
author_rank: Newbie
timestamp: September 21, 2022, 12:29:00 am
content: I have a Sencore LC-102 that worked well for a number of years until 2019 when one day it failed to start. That year I found an experience Sencore repair tech that had been involved in repairing Sencore cap testers. Sent it to him and he started on it and then put it to the side waiting for parts to come from the EU. His health went downhill and I would call him every few months and have a long talk with him and get a promise to get back on it as soon as he felt better. Well, last week his Wife, now his widow called to confirm my address. She is sending the unit back to me.Bottom line anyone know anyone that can and is willing to repair this unit. I was told that this is bear to fix.JB

author: Simon
author_rank: Unknown
timestamp: September 21, 2022, 06:31:55 pm
content: Please do not double post, it severely pisses other uses off.
Sencore LC-103 Issue - Page 1
Forum section: electronics / repair

author: Sambo521
author_rank: Newbie
timestamp: August 15, 2023, 07:00:46 pm
content: Hey Guys,My LC103 has developed a problem as of late and wanted to pass the symptoms around to see if anybody else has experienced this before:The meter basically works great on every mode but leakage test.The meter lead zero functions correctly, the cap value function works correctly, Inductor test works correctly,ESR acted a little funny as it sometimes would give a negative value, but the leakage function is amiss.Below 50 Volts the leakage function works fine best I can tell, above fifty volts the progress bar only moves about 1/4 the way over and fluctuates some.It's been doing this for a while.measured voltage on the red and black wires between the two pc boards and it shows about 50 volts when checking for leakage at 100 volts.Curius that everything seems to be in threes on what I guess is the voltage generator board.Thanks for your thoughts on this.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 16, 2023, 12:02:48 am
content: you have som schematics and other stuff therehttp://www.ko4bb.com/getsimple/index.php?id=manuals&dir=06_Misc_Test_Equipment/Sencore/Sencore_LC103

author: floobydust
author_rank: Super Contributor
timestamp: August 16, 2023, 01:46:38 am
content: There are 0.2, 2, 20mA range selects for leakage, as well as the leakage DC-DC voltage 32-1,000V. I would see if the power supply is working for that, at K1.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 16, 2023, 09:28:28 am
content: on the same website, you had the lc102, and if i recaLl there was some psu voltage generator check listthe lc102 had history of some bad relay in them, the big one and sometimes one of the small one(s), the lc103 may suffer the same fate ??be sure the open and close calibration pass all the way ....they need good wires with specific resistance AND capacitance rg63 i think unless you have the original one ...

author: Sambo521
author_rank: Newbie
timestamp: August 16, 2023, 06:23:13 pm
content: I appreciate the link!Now to do some logical thinking.
Sencore LC101 Calibration Manual Available? - Page 1
Forum section: electronics / repair

author: mr.fabe
author_rank: Regular Contributor
timestamp: April 01, 2018, 12:32:40 am
content: I just got my hands on a Sencore LC101 and found that the capacitor values are running almost 20% higher when compared to a Fluke 87V and Sencore LC53. The leads have been zeroed out for capacitance using the combination rear and front pots. Does anyone have a link or a copy of the calibration manual and or schematics for this model?Thank you

author: WA2SQQ
author_rank: Newbie
timestamp: February 04, 2019, 04:20:28 pm
content: I also have an LC101 that has developed a strange problem. The rear "zero set" jumps from "016" down to "-017" - just skips over the "zero" point. I verified the pot is OK. Anyone have any ideas? Even a link to the schematic for LC101 would be appreciated. Respond please to wa2sqq@gmail.com

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: May 25, 2019, 02:47:38 am
content: Call me part of the "me too" movement.I have found no schematic for at least 10 years now.I too have the jumpingzero set.I have found that one must check all of their push crimp plugs. Any movement of these plug to board connections comprimises the integrity of the crimp.I have soldered the wires in the nylon plugs. Not for those who have full sense of smell. I am going to replace them eventually with some Chinese JST's. At least they don't go bad unless you do something bad.There must be a copy somewhere out there on the intertoobs.Quote from: WA2SQQ on 2019-02-04, 12:20:28

author: mr.fabe
author_rank: Regular Contributor
timestamp: May 25, 2019, 02:04:02 pm
content: The Sencore LC101 calibration guide and schematics are available from Choice Electronics if you need them...http://www.choicegear.net/
Sencore LC102 Continues Beep - Page 1
Forum section: electronics / repair

author: glicos
author_rank: Regular Contributor
timestamp: May 04, 2024, 12:46:32 pm
content: I have an LC102 that is previously working perfectly. Stored it and never been use for almost 1 year. But when I turn it ON, there is a continues beep. Readings are all ok, can run short and open test and passing. The beep is very annoying. Any help will be appreciated..

author: coromonadalix
author_rank: Super Contributor
timestamp: May 04, 2024, 01:58:13 pm
content: http://www.ko4bb.comschematics are therenot suppose to beep continously for sure ... unless some bad contacts or humidity

author: glicos
author_rank: Regular Contributor
timestamp: May 05, 2024, 10:43:13 am
content: Thanks for the inputs. Yup, I thought it was just an open input fuse. But fuse is ok. Will update this post once i identify the problem
Sencore LC102 not powers ON - Page 1
Forum section: electronics / repair

author: anddrej
author_rank: Newbie
timestamp: September 06, 2023, 07:27:50 am
content: I purchased LC102, tooked laptop PS (18V) and unit powers ON without any problems. As unit stays somewhere on dirt, behind foil, which is in front of display i decided to remove front and cleaned.I did this and at the same time i found also that that 4 connectors, which have wires only pressed in...were ...hmm...not the best as some wires just fall out, so i replaced all 4. Must note, that i replaced wire by wire so no posibility to mix them between. After put all together unit not powers on. I didn't looked much just checked if voltage came to 317 and yes...on IN is 18V and on OUT is 14V.I said before imstarting to invent warmeater will ask specialists here who knows well some well known issues with this unit...so guys...is there something which could be problem?I have all documentations...also all schematic combined together...so i already prepared myself for the worse:)Thank yoiu.Andrej

author: coromonadalix
author_rank: Super Contributor
timestamp: September 06, 2023, 10:33:27 am
content: if i recall theses connectors are crimped, if one or many wires are not fully pushed into the connector ....you need the proper tool not just an screwdriver trick to push the wires inside ...

author: anddrej
author_rank: Newbie
timestamp: September 06, 2023, 12:27:20 pm
content: Hello,Yes i read about those and after i just replaced all connectors unit works...again.
Sencore LC102 "Short" - Page 1
Forum section: electronics / repair

author: ScottSerpa
author_rank: Newbie
timestamp: March 28, 2024, 03:32:47 pm
content: I apparently posted this is the wrong forum (test equipment). Sorry, newbie mistake.I have an LC102 that I purchased new many many moons ago. I think I had it calibrated once by Sencore but other than that one time, it's been working fine. All of a sudden the display reads "Short" when testing a capacitor or zeroing "Open". I found L1 stuck, replaced it but that made no difference. Additionally I found the 2N6557 shorted. I replaced it with a NTE 171, but that also made no difference. I read 51 Ohms at the BNC so it's not an input short. I've seen others with this same issue, just wondering if anyone has found a solution.Thanks,Scott

author: mawyatt
author_rank: Super Contributor
timestamp: March 28, 2024, 03:45:12 pm
content: Locate a schematic and post, then we might be able to assist in helping locate the problem. Also images of the inside and PCB will help.Best,

author: coromonadalix
author_rank: Super Contributor
timestamp: March 30, 2024, 06:31:29 am
content: schematics are at ko4bb website
Sencore PA81 Is this a factory mod? - Page 1
Forum section: electronics / repair

author: Bargainhunter
author_rank: Regular Contributor
timestamp: June 19, 2025, 10:13:55 pm
content: I'm repairing my PA81 and I see what appears to be a user mod. It does not appear on any of my schematics.However I found a video on youtube which shows the same mod. There are two 100uf capacitors added to transistors TR7 and TR8 (see attached photo).Does anyone have a schematic that shows this mod?Thank you.

author: Dougmc
author_rank: Contributor
timestamp: June 28, 2025, 02:09:29 am
content: These guys may be your best bethttps://groups.io/g/SencoreOwnersGroup
SENCORE PR57 AC POWERITE Switch and Switch Cap Source - Page 1
Forum section: electronics / repair

author: Voxman
author_rank: Contributor
timestamp: October 31, 2020, 07:37:38 pm
content: Hello Everyone!(2nd attempt to post this)I’m restoring an old Sencore PR57 POWERITE power supply that has 2 switches where the push button caps have broken off. I have one cap but need an additional one. Also I doubt there is enough part of the switch to be able to successfully reattach the caps. The switches involved are all part of an interlocking system however I’m sure they are individually replaceable if I could find a source. I apologize that I don’t have a photo of the actual switch yet but if no one out there knows what type of switch this Sencore uses, I’ll have to disassemble my unit to see what it is ( big PIA because it’s installed in a tight test bench ). I’ve noticed Sencore uses these switches and caps on a lot of their equipment.Haven’t been able to find any source for these parts yet on eBay and a few of the sites recommended here in the replacement knobs, etc. forum.Thanks in advance for everyone’s advice and input. I’m even hoping somebody out there might have these parts laying around!Gary
Sencore PR570 Isolation Transformer Service and Calibration Info Needed. - Page 1
Forum section: electronics / repair

author: KG7AMV
author_rank: Frequent Contributor
timestamp: November 08, 2023, 08:43:41 am
content: Hello, Everyone.I have looked and I cannot seem to find the Sencore PR570 Isolation Transformer Service and Calibration Info?Anyone have a copy of this info handy?I have 2 of them now and want to make sure I have the documents.Thanks.

author: fmashockie
author_rank: Frequent Contributor
timestamp: November 09, 2023, 06:56:42 am
content: I can't be of help on the documents, but I just wanted to say these are awesome! I wouldn't mind having oneI have a Sencore PR-57 that I use constantly. You don't find too many isolation/variacs in one package.

author: KG7AMV
author_rank: Frequent Contributor
timestamp: November 13, 2023, 06:35:57 pm
content: I did find some High Resolution 600DPI Sencore PR570 Schematic & Block Diagram's Posted them on my Blog.https://www.stevenrhine.com/?p=132208So far no luck on the service / calibration info not even form sencore themself..

author: Jwillis
author_rank: Super Contributor
timestamp: November 13, 2023, 08:43:47 pm
content: The schematic has expected conditions at the test points. If you have a oscilloscope and DMN, start from the supply transformer and work your way to the front. Test supply voltages first to each block. Them check inputs to each block then outputs. The data sheets for each component will give operational parameters and limits. For example, the LCD drivers look like ICL71XX series A/D converters which only has the reference adjustment.Looks kind of straight forward which leads me to believe the reason for the lack of a dedicated service manual.

author: KG7AMV
author_rank: Frequent Contributor
timestamp: November 13, 2023, 09:23:56 pm
content: Jwillis, You will see at the TP it will say See Note XX we do not have the notes and from past experience in other equipment there is a sequence for adjusting these if required.
sencore sc61 - Page 1
Forum section: electronics / repair

author: pete g
author_rank: Regular Contributor
timestamp: December 25, 2021, 02:09:59 am
content: hi all, merry xmas. i own the sc61 scope. the only problem i'am having concerns the lcd readout.it shows eights and all the parameters its capable of measuring, i.e. freq. voltage etc. these stay on the screen and no amount of manipulation has no effect. i've checked all the rails(good), checked for bad caps and ripple. checked all the plug in boards for bad connections. i have another scope i can use to troubleshoot the sc61. sure would appreciate some help. thanks.

author: CaptDon
author_rank: Super Contributor
timestamp: December 25, 2021, 04:04:43 pm
content: The biggest problem we had on the SC61 Sencore scope at the radio station was crappy pushbutton contacts. They were always messed up. It was a constant battle. That scope was the engineering departments pride and joy when it was new, but after only about 1 year it had more problems than any other scope would be expected to have after 10 years of hard use!!

author: pete g
author_rank: Regular Contributor
timestamp: December 25, 2021, 10:44:57 pm
content: hi, actually the rest of the scope works perfectly. it doesn't get a lot of use. just the readout is a problem.

author: CaptDon
author_rank: Super Contributor
timestamp: December 26, 2021, 02:50:19 am
content: I wonder if the readout was done with one of those 40 pin 'everything in one package' DMM I.C.'s?? It would be interesting to have a look at the schematic. I think the SC60/SC61 schematics are available. It may have been included in the owners manual like the old Tek gear was. As I recall the multimeter functions were switched separately from the vertical functions of the scope and our buttons were always only semi-functional. I think we bought ours around 1983?

author: pete g
author_rank: Regular Contributor
timestamp: December 26, 2021, 02:54:03 am
content: the buttons seem to work ok. what would happen if some of the chips had no clock pulse?
sencore sc61 scope - Page 1
Forum section: electronics / repair

author: pete g
author_rank: Regular Contributor
timestamp: June 09, 2023, 08:10:35 pm
content: hi all, this scope works good except for the digital readout. the readout displays all the parameters its capable of measuring. if you select one parameter, ie frequency nothing changes on the display. did anyone have the same problem with this scope? if not, hopefully an educated guess at what could be wrong?

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: June 09, 2023, 10:39:06 pm
content: Did you follow the directions in the manual??Page 38.file:///tmp/mozilla_mint0/Sencore--SC61--user--ID12849.pdfI believe the trace needs to be on the screen and stable (triggered) for the fist method of obtaining the freq. ie Main Counting Channel.This measures the frequency of the signal used to trigger the scope.There are two methods of obtaining the freq readout which are described in the manual.The second method requires a larger signal.See if either of these methods work.

author: pete g
author_rank: Regular Contributor
timestamp: June 09, 2023, 11:23:32 pm
content: prior to this present problem, i had no trouble reading the freq output. i've had the scope for awhile now and it worked fine on p-p volt and freq.
sencore sc61 scope - Page 1
Forum section: electronics / repair

author: pete g
author_rank: Regular Contributor
timestamp: October 06, 2019, 05:58:44 pm
content: hi members, need help with scope. chan b freq readout not working. anyone, have similar problem?

author: SES Audio
author_rank: Newbie
timestamp: January 12, 2020, 02:44:38 pm
content: I have a few of these scopes but haven't had any issues with the LCD display.If you find that the issue is only on channel b , I'd try flushing the Channel B Freq gang switch with DeOxitDo you have a copy of the schematics/service manual?
Sencore VP401 Repair - Page 1
Forum section: electronics / repair

author: BlabTech
author_rank: Newbie
timestamp: March 13, 2025, 01:31:14 am
content: I have a blown transistor (Q6) in my VP401. The transistor is too damaged to be able to read what is printed on the transistor. I have been unable to find any service information on it. Does anyone know what transistor this is so I can find a replacement?

author: Swake
author_rank: Frequent Contributor
timestamp: March 13, 2025, 07:51:37 am
content: What is that transistor doing in the circuit? Post a close up pic of the board and the things around that Q6. If we can find out what it is doing it might be possible to identify a replacement part. You might have to end up reverse engineering a small part of that board.

author: Swake
author_rank: Frequent Contributor
timestamp: March 13, 2025, 07:59:09 am
content: Is this Q6 ?At first sight it might have a very similar function to Q5 and Q7. Very near to the composite output connector.

author: BlabTech
author_rank: Newbie
timestamp: March 13, 2025, 12:37:38 pm
content: I have attached a few pictures. I was using the RF portion when it went out. Had a test pattern on channel 4 (US). Battery was getting low so I plugged the charger into it and it when out.

author: Swake
author_rank: Frequent Contributor
timestamp: March 13, 2025, 01:17:59 pm
content: How does that Q6 relate to the charging circuit? You'll have to trace the circuit a bit. What are on U11 and Q5 and so on? I cannot read it from the pictures.How is the battery connected, is that via J7?

author: BlabTech
author_rank: Newbie
timestamp: April 06, 2025, 06:02:50 pm
content: Yes, J7 is where the battery board plugs in. I removed it to get a better picture. No suret if Q6 was related to the charging circuit. I was just stating what I was doing when it went out. Here is a picture of Q6 off a different board.

author: Swake
author_rank: Frequent Contributor
timestamp: April 06, 2025, 06:38:17 pm
content: This list are possibilities that are known to be marked 'SP'.You'd have to carefully measure the package to determine exact size, that will allow to exclude at least some.Then you might also want to consult the datasheets of these components to verify which one matches your situation. This also means that you'll probably have to reverse engineer somewhat to understand in what context that component is used.Code:SPSDMP0340LCTSOT-523Dual, Schottky, Sw, 40V, 200mA, 150mW, 2pFSPMCP120-485ISOT-234.72V+150mV, -Reset ODOSPBSS84SOT-23V-MOS, LogL, 50V, 130mA, 250mW, <10 Ω(130mA), 3/7nsSPAX6906GRSOT-23-3L2.25V±1.5%, +Reset PPOSPAPX809S05-31SR-7SOT-233.08V±1.5%, -Reset PPO, 50ms Rt delaySP2SC4619-PSOT-416GP, 30V, 50mA, 150mW, B=82..180, 110MHzSP2SC4100-PSOT-323AF, 30V, 50mA, 200mW, B=82..180, >110MHzSP2SC3082K-PSOT-346AF, 30V, 50mA, 200mW, B=82..180, >110MHz
Sercos receiver replacement - Page 1
Forum section: electronics / repair

author: gaminn
author_rank: Frequent Contributor
timestamp: November 01, 2022, 04:18:14 pm
content: Hi, my servodriver has Honeywell HFD7000-501 sercos receiver mounted. Unfortunatelly I dropped the driver and the connector of the receiver broke. Anybody, any idea where to find this receiver or a replacement?
Series connection of thick copper based inductors - Page 1
Forum section: electronics / repair

author: jm_sanz
author_rank: Contributor
timestamp: December 05, 2022, 04:04:47 pm
content: Good afternoon everybody,I am working on some inductors (attached) with thick rigid copper wire (2.5mm of diameter):https://www.tme.eu/en/details/dne2.50_0.50/coil-wires/bq-cable/dn1e2-50-0-50/I am planning to use them with 15A, 1 KHz and would like to connect some in series.Do you have any idea of the best way of connecting them in series? I have thought about a connector like the one attached but there might be a better way as this is gonna get hot. Soldering can be complex as prefer to connect them and disconnect them easily.Thank you in advance.

author: jonpaul
author_rank: Super Contributor
timestamp: December 05, 2022, 05:10:35 pm
content: crimp splice or solder with hook shaped joint.Strip magnet wire insulation with Xacto knife, tin magnet wire, strip with knife second time before soldering.Same stripped needed with crimp.The terminal stripes pictured are not so reliableJon

author: vidarr
author_rank: Frequent Contributor
timestamp: December 05, 2022, 05:51:43 pm
content: Unscrew the screws of those connectors you show. Then, tap the metal connector out of the plastic housing and put the screws back in. Use them like that. You can screw/unscrew as much as you want. Nothing to melt. Just don't touch them when live.

author: Gyro
author_rank: Super Contributor
timestamp: December 05, 2022, 07:22:13 pm
content: Quote from: jm_sanz on December 05, 2022, 04:04:47 pmHigh temperature glazed ceramic versions of the terminal block you showed are easily available. Just search 'ceramic terminal block'.
Service information for Meridian 508 CD player. - Page 1
Forum section: electronics / repair

author: CHexclaim
author_rank: Regular Contributor
timestamp: February 02, 2023, 03:53:50 pm
content: Hello everyone.I have on the bench today a Meridian 508 CD Player. Can anyone help with a source for service information (service manual, schematics, etc.)?I cannot find anything online and, as you all know, repair process is much straight forward an professional when having the correct documentation.Thanks a lot! Charlie.

author: Runco990
author_rank: Frequent Contributor
timestamp: February 03, 2023, 11:29:37 pm
content: Sadly I do not, but I have found that 99% of the time the optical pickup is done and needs a new one. Which is available.Maybe you don't even need a diagram.Best of luck!

author: CHexclaim
author_rank: Regular Contributor
timestamp: February 04, 2023, 01:24:41 am
content: Thank you for your reply. Yes, it seems to be that, but, having the service manual is always a better start.Thanks again. CH
Service information needed: Xitron 2000M calibrator - Page 1
Forum section: electronics / repair

author: D2236
author_rank: Regular Contributor
timestamp: December 14, 2024, 06:14:57 pm
content: Hi,My XITRON 2000 calibrator developed a problem after being in daily use for many years. The current output is stuck at about 20 mA and the voltages are only correct under 2 V. The maximum voltage output is about 2.3 V.I have emailed Xitron/Vitrek to ask for any diagram or service information, but they never bothered to reply. Is there any member who can share any diagrams or service manual to facilitate repairing the unit?All help would be greatly appreciated.Thanks,I found some old thread regarding this instrument and repair, but since the last post was older than 120 days, the warning message suggested creating a new topic.https://www.eevblog.com/forum/metrology/xitron-2000m-(teardown)/msg3451792/#msg3451792Update: It turns out that one of the digital isolators (ADUM2400) was faulty in the unit. Unit is back to normal operation.
Service manual and/or schematics for Micromaster LV48 - Page 1
Forum section: electronics / repair

author: giosif
author_rank: Frequent Contributor
timestamp: March 02, 2020, 05:17:56 pm
content: Hi,Does anyone here happen to have any servicing info on the Ice Technology Micromaster LV48 programmer?If so, would you be so kind to share that info with me, please?I got one such device from eBay as faulty and am trying to see if I can resurrect it.Thanks!

author: coromonadalix
author_rank: Super Contributor
timestamp: March 02, 2020, 06:34:25 pm
content: Possibly an rebadged Elnec programmer, same familly than chipmaster 6000, dataman, and other models .... Elnec call them odm "brand"modelsNever saw an leaked service manualhttps://www.elnec.com/en/distributors/odm-product-names/

author: giosif
author_rank: Frequent Contributor
timestamp: March 17, 2020, 08:55:14 pm
content: They do look somewhat similar but they are not the same: the Micromaster was made by Ice Technology, a UK company that went bust.Well, sort of - there is still a surviving part, based in US, but they don't seem to have any knowledge of these old programmers.Anyone reading this who actually owns a working LV48?

author: giosif
author_rank: Frequent Contributor
timestamp: April 06, 2020, 08:27:33 pm
content: Just an update to say that, in the end, I was able to fix this programmer.The culprit - two partially dead MC74HCT273AN octal flip-flop ICs.The behaviour of the unit when I first checked it was that most of the tests in the self-test were failing and, at the end, the programmer would stop responding.In absence of any servicing info, I tried checking the more susceptible components, starting with the bottom board.This one has the power supply section, as well as the main processor, an SRAM IC, one EEPROM and one FPGA.And, since running the self-test while connected to a PC did recognize the programmer and it was able to check that the SRAM was good, I concluded that most of these components are likely to be fine.I also swapped the FPGA IC between the bottom and top boards and I could see no difference in behaviour (so, either both were bad, or both were good).In any case, after some more investigation, I concluded the bottom board is most likely ok.Next, I focused my attention to the top board, which is full of ICs and transistors.Checking the transistors was straightforward, but the ICs were a different story.So, I decided to desolder all of them and try to check them individually.I used this opportunity to install IC sockets, so I could remove/swap any ICs on the board easily.Checking the ICs one by one, I was able to identify the two broken ICs.After replacing them, running a self-test worked all the way through, with no errors reported.I also did some EPROM and EEPROM reading/burning checks against my otherwise trusty TL866II and all is good.Ok, not a multimeter, but you get the idea.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 13, 2022, 02:50:00 pm
content: Software for this programmer is here :http://electricstuff.co.uk/winlv.html
# Service Manual for a Philips/Fluke PM 3375 - Page 1
Forum section: electronics / repair

author: firefly-10
author_rank: Newbie
timestamp: April 26, 2022, 11:06:33 pm
content: Hi guys,I bought a Philips/Fluke 3375 very cheap and since it is already some years old, I am looking for the service manual for this old oscilloscope.On the Internet I have often found the user manual, but unfortunately never the service manual.Does anyone know where to find it, or does anyone have it as a PDF somewhere on his hard drive?I would be happy if someone still has something like that, even if the oscilloscope is already a little older.GreetingsDirk

author: HobGoblyn
author_rank: Unknown
timestamp: April 27, 2022, 12:19:45 am
content: Uploaded it to wetransfer. Link valid for next 7 days,https://we.tl/t-CwWv3yiWpfOr you can download from (but make sure you click on the “I’m not a robot” and not any of the other crap)https://elektrotanya.com/philips_pm3365a_67a_75_77_oscilloscope_sm.pdf/download.html

author: firefly-10
author_rank: Newbie
timestamp: April 27, 2022, 12:35:08 am
content: Quote from: HobGoblyn on April 27, 2022, 12:19:45 amThank you very much !!!That was what I was still missing. Hope that the PM 3375 does not have too many problems. End of the week it will be delivered, then we see how well it is preserved.Thanks again !GreetingsDirk
Service Manual For Agilent B2911A Precision Source / Measure Unit - Page 1
Forum section: electronics / repair

author: heroxue
author_rank: Newbie
timestamp: January 11, 2024, 04:19:58 pm
content: Hello everyone，Do any of you have the service manual or schematic diagram for the Agilent B2911A Precision Source / Measure Unit? My source measure unit suddenly burned out while not in use, with a hole burnt in the analog output board, the output relay destroyed, and the copper traces on the PCB melted.

author: TheSteve
author_rank: Unknown
timestamp: January 11, 2024, 04:47:05 pm
content: There are no docs for it, not even info on how to calibrate it.I have a spare output board, but it is untested.
Service Manual for Chroma 12061 - Page 1
Forum section: electronics / repair

author: Jwildesbr
author_rank: Newbie
timestamp: September 19, 2024, 01:23:52 pm
content: Hi,I am searching for Service Manual of Chroma 12061 multimeter.It present errors after run the selt test.Any recomendation to fix it?Best regards,Jfarias

author: squadchannel
author_rank: Frequent Contributor
timestamp: September 19, 2024, 02:08:36 pm
content: It looks very keithley 2100.I did an image search and it looks like kikusui DME1600 and Picotest M3500A are also rebadged.

author: Jwildesbr
author_rank: Newbie
timestamp: September 19, 2024, 02:30:13 pm
content: @squadchannel really, all models that you listed looks like Chroma...but i try searching for Service Manuals for each one and nothing found.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 19, 2024, 02:52:51 pm
content: picotest m3500 SV but not sure they have schematics ... if i recall they are clones of keithley ...https://elektrotanya.com/picotest_m3500a_service_manual.pdf/download.html#dl94 pages, maybe there is one with moreyou had the k2000 reversedi posted therehttps://www.eevblog.com/forum/testgear/keithley-2100array-m3500-750-vac-range-bolloxfied!!/user manual codes snippets etc ...https://www.kusamelectrical.com/pdf/M3500A%20Manual.pdf

author: coromonadalix
author_rank: Super Contributor
timestamp: September 19, 2024, 11:53:44 pm
content: some fw for the m3500 use at your own risk
Service Manual for Fluke 8060A Multimeter? - Page 1
Forum section: electronics / repair

author: Axtman
author_rank: Regular Contributor
timestamp: September 12, 2019, 10:41:25 pm
content: Does anyone have the service manual with calibration procedures for a Fluke 8060A handheld multimeter? I think I have the 300v model (vs. the 1000v model) but am not sure how to tell. Thanks!Because of it's age should I just "shotgun" recap all the electrolytics? Thanks.

author: dacman
author_rank: Frequent Contributor
timestamp: September 12, 2019, 11:00:35 pm
content: Click the below link and enter a search term of 8060A:https://www.fluke.com/en-us/support/manuals
Service manual for Klein & Hummel O 800 subwoofer - Page 1
Forum section: electronics / repair

author: okw
author_rank: Frequent Contributor
timestamp: July 19, 2020, 11:16:30 am
content: Hi guys. I'm looking for a service manual for my fathers Klein & Hummel O 800 subwoofer. I get a lot of hits on Google, but need to register my credit card to download. That's not gonna happenAnyone of you have the service manual?The subwoofer powers up, but there is no sound. He opened the case and looked over it. No loose wires, nothing looks burned (by his eyes), but I'm not with the speaker myself (he lives a few hours away) so I haven't taken any measurements yet. Any clues before I start?
Service Manual for Pioneer DJ DJM 900 Nexus 2 - Page 1
Forum section: electronics / repair

author: jmibk
author_rank: Regular Contributor
timestamp: July 30, 2019, 04:54:42 am
content: Hi,I have a DJM 900 Nexus 2 DJ Mixer for repair (strange behavior on LED lighting at the front site) and need the service manual, at least a schematic diagram for it.Does anyone have and can send it to me (jmibk0<at>gmail.com)?I asked already our pioneer shop, they told me that he can't get it because pioneer has to scan it and it takes too much time.Thanks at all!

author: lekso
author_rank: Newbie
timestamp: July 30, 2019, 05:42:07 am
content: https://elektrotanya.com/showresult?what=Pioneer%20DJ%20DJM%20900%20Nexus%202&kategoria=&kat2=all

author: jmibk
author_rank: Regular Contributor
timestamp: July 30, 2019, 06:20:07 am
content: Hi,this is for another model. There is a "DJM 900 NXS" and a "DJM 900 NXS 2" - I need it for the "2" version, that I cant find on the internet.
Service Manual for Profex CM14S plus and flyback? - Page 1
Forum section: electronics / repair

author: wurzel42
author_rank: Contributor
timestamp: May 30, 2020, 06:42:37 pm
content: I have another vintage CRT here. A Profex CM14Splus. It works fine but has one slight problem: after 2 minutes running I get a slight wobble moving from bottom to top where every alternating line is shifted by a pixel roughly. Plus I think I can hear a slight hum during that. It stops after one minute and the monitor runs fine for an hour after that. Any ideas what it might be? Flyback dying...?Incidentally, here are some pics from the innards. Can anyone identify the flyback in there? If I ever need a replacement...

author: fzabkar
author_rank: Super Contributor
timestamp: May 31, 2020, 09:05:18 am
content: The flyback transformer is inside the metal enclosure in the 4th photo. The "EHT" lead should connect to the CRT anode.

author: wurzel42
author_rank: Contributor
timestamp: May 31, 2020, 11:12:04 am
content: Yeah, I figured that out as well. Question is: how can I identify the model so I can eventually get replacement parts?

author: fzabkar
author_rank: Super Contributor
timestamp: May 31, 2020, 07:12:57 pm
content: The part numbers on the flyback transformer and other magnetic parts usually provide clues for identifying the chassis.

author: wurzel42
author_rank: Contributor
timestamp: June 02, 2020, 01:45:25 pm
content: Quote from: fzabkar on May 31, 2020, 07:12:57 pmOkay, next time I open up the monitor, I will try to figure out more about the transformer. I will also try to disassemble the thing further so I can get to the deflection PCB and check up on the solder joints.

author: inse
author_rank: Super Contributor
timestamp: May 22, 2021, 11:23:11 am
content: I just picked such a monitor from the scrap and would like to use it on my Commodore 128.Unfortunately it has issues and does not synchronize, furthermore the EHT seems to be too high.Did succeed finding a service manual?

author: inse
author_rank: Super Contributor
timestamp: May 27, 2021, 03:50:45 am
content: In the meantime I have been able to fix the EHT issue: the resonance capacitor has been faulty.But it still won't synchronize to the video signal, it looks like the TDA2595 is defect as well.
Service manual for Tecsun PL-880 'flagship' receiver? - Page 1
Forum section: electronics / repair

author: peteb2
author_rank: Regular Contributor
timestamp: May 26, 2019, 10:41:51 pm
content: Have done an indepth Google to find any info but i expect Tecsun are doing their best to keep things among their agents.I bought one these receivers less than 5 months ago from Amazon and while using the ordinary medium wave AM band one afternoon, the thing suddenly let out a loud as hell buzzing noise and then only hiss. The entire AM band is now silent save for hiss. The LW, HW, SW & FM stills works 100%.On account of being so far down-under in NZ the cost to return the PL-880 under warranty is beyond being sensible. I've opened the thing up breaking the seal (too bad) and discovered one of the most terrible assembly jobs ever on such a kind of equipment. I am used to the likes of the extreme quality of Sony or Yaesu RF gear but this thing is a JOKE.The PCBs have been truly badly flow soldered and there are micro-balls of legacy solder paste everywhere. Screen cans have been badly (manual) half soldered to the board and i won't go into further detail here on just what a mess things really are.My option now is to obtain service manual or at least any service info and sort this thing otherwise it will go into being another reason NOT to buy this kind of OneHungLow Brand of equipment.Such a pity, nice looking, fully optioned unit & reasonably great performance with rave revues but in reality zero reliability all because of truly low assembly standard.

author: Unknown
author_rank: Unknown
timestamp: May 27, 2019, 09:07:49 am
content: Quote from: peteb2 on May 26, 2019, 10:41:51 pmHaving been inside something like 40 or 50 Tecsun radios - mostly PL-600's, 660's, and 880's - for modding (e.g. IF output) or repair reasons (mostly rotary encoders on early build ones, & headphone/antenna sockets on later units), I'm surprised. Their physical build quality has always been right up there with the best Chinese manufactured stuff I've ever seen. I've certainly never seen anything even remotely like you describe.Ihaveseen that sort of thing from the likes of Kaito or the OEM'd cheap Ali/Banggood specials, but not Tecsun. Either it's a very bad one-off, they've taken a massive dive in quality recently, or someone has started selling fakes.Unfortunately I've never seen that sort of fault (odd that it's only affecting MW & not SW), nor do I know of any genuine service manuals or schematics - just a number of 'unofficial' schematics that are either poorly reverse-engineered, or just obviously BS wrong. And I don't think I've even seen one of those for the '880.edit: turns out I do have a (Russian, reverse-engineered) PL880 schematic. Hope it helps. Still can't quite see what'd affect MW but not LW/SW.
Service manual for Tektronics TDS3000 series? - Page 1
Forum section: electronics / repair

author: JMcC
author_rank: Contributor
timestamp: May 21, 2022, 06:51:54 pm
content: I'd like to get my hands on the service manual for these scopes. In other threads, I saw a link to what is suppsed to be the service manualhttp://exodus.poly.edu/~kurt/manuals/manuals/Tektronix/TEK%20TDS%203000%20series%20Service.pdf.Howwever this link appears to be dead.The scope I have is a TDS3034. Can anyone help?Thanks,J

author: james_s
author_rank: Super Contributor
timestamp: May 21, 2022, 06:54:22 pm
content: It is unfortunately a bit of a joke as far as service manuals go.

author: JMcC
author_rank: Contributor
timestamp: May 22, 2022, 08:32:19 am
content: @james_s, thanks for that. You're right about the qualty sadly. That said there is so little you can do with these. I have one that had a couple of kV applied to one of the inputs. Think the best I can hope for is to isolate the affected channel and maybe the others will be OK.J.
Service manual for VGD-3000 RM UPS - Page 1
Forum section: electronics / repair

author: niasha
author_rank: Newbie
timestamp: October 25, 2020, 08:34:23 am
content: Hello All,Recently one of my UPSes blew up. The attachment contains a photo of what is going on inside it. I'm looking for the service manual, any help will be greatly appreciated.Info about UPS :http://www.powercom-usa.com/ProductDetail.asp?ID=2306Thanks

author: TheMG
author_rank: Frequent Contributor
timestamp: October 25, 2020, 05:37:02 pm
content: Unfortunately it is VERY unusual for manufacturers to release service documentation for smaller UPS models, aside from a few leaked schematics for some older APC models, I've had no luck finding anything even for some of the bigger manufacturers (APC, Eaton, Alpha, etc). However, you've got nothing to lose by trying, have you already tried contacting the manufacturer?That being said, with some knowledge about SMPS and UPS circuit theory and typical topologies, repairing them is not usually too difficult.-All the MOSFETs should be replaced, even if they show no signs of physical and test ok.-Thoroughly clean the PCB of any carbon from the burnt MOSFETs, as this can be conductive.-Check the gate resistors for any open or out of tolerance resistors.-Check gate drive circuitry for proper operation, this can be done by powering up the UPS from battery BEFORE installing the new MOSFETs, and using an oscilloscope to check for a gate drive waveform. A DSO is preferred since the UPS will most likely shut down very quickly once it detects a fault due to the missing MOSFETs. I usually connect the scope and set it up in single-shot capture, then power the UPS on. If everything is ok you will usually see a few cycles of switching waveform before the UPS faults off.-Once verified that the gate drive is functioning properly, install the new MOSFETs and hope for the best!

author: Andy Watson
author_rank: Super Contributor
timestamp: October 25, 2020, 06:01:25 pm
content: These any good? They are quite old, embedded in DOC files but possibly better than nothing.https://elektrotanya.com/powercom_vanguard_vgd_series_ups_sch.rar/download.html
need service manual for Yamaha RX-V683  - Page 1
Forum section: electronics / repair

author: rexjred
author_rank: Newbie
timestamp: August 30, 2019, 01:38:47 am
content: Need a service manual for Yamaha receiver RXV683.

author: mzacharias
author_rank: Frequent Contributor
timestamp: August 30, 2019, 11:44:27 am
content: What's the issue?

author: rexjred
author_rank: Newbie
timestamp: August 30, 2019, 05:17:40 pm
content: ps2 prt-0001 error code in diagnostic mode. receiver turns and immediately shuts off. I think its the IC78 transistor.

author: cowasaki
author_rank: Frequent Contributor
timestamp: August 30, 2019, 10:09:07 pm
content: I've just put a bid in on a RX-V 620RDS that also turns itself off moments after switching on.... Had to be worth £20

author: rexjred
author_rank: Newbie
timestamp: August 31, 2019, 12:00:36 am
content: how does that help me?I wonder if the 673 manual has the same circuit board for the power supply 2 schematics

author: mzacharias
author_rank: Frequent Contributor
timestamp: August 31, 2019, 03:14:46 am
content: Quote from: rexjred on August 30, 2019, 01:38:47 amSend me your email address tomark_zacharias@sbcglobal.netand I can send the manual in RAR chunks - may be too large for your provider to accept as a single attachment.

author: sunny45
author_rank: Newbie
timestamp: November 08, 2021, 12:09:27 pm
content: Please, send me the service manual for the RX-V683 too... on my receiver there is a problem with the display, it´s now too darkuntil now, I tried first power cable off and second a factory reset .. both didn´t help.Now I think it could be a problem with one or two capacitors on the power supply board for the VFD display.Do you know the value of them? So i could bye them before tearing the receiver apart.thx

author: mzacharias
author_rank: Frequent Contributor
timestamp: November 08, 2021, 02:05:50 pm
content: Quote from: sunny45 on November 08, 2021, 12:09:27 pmemail me here and I can send the manual. mark_zacharias@sbcglobal.net

author: sunny45
author_rank: Newbie
timestamp: November 08, 2021, 09:57:31 pm
content: thxin advance.my email is cgaert-add-gmail.comrgds

author: sunny45
author_rank: Newbie
timestamp: November 12, 2021, 07:00:10 pm
content: Hi,I got iit.. many thx

author: jimmysolisn
author_rank: Newbie
timestamp: August 21, 2023, 02:19:16 pm
content: I have a problem with zone 2, i tried every setting, but still no signal from zone 2 out to external amp, please send me service manual, to jimmysolisn@gmail.com

author: pienari
author_rank: Regular Contributor
timestamp: April 07, 2024, 03:33:32 pm
content: Like few other Yamaha amps same issue.I have repaired RX-V1000.Amp started to service mode and give few errors.I looked for net and everyone told to chance capacitor to pre psu.It not help at all.I started to measure voltages and find that few was totally missing.After totally disabled the amp i found power regulator in front of the amp was totally loose .I soldered it again and no error codes.
service manual Ground Zero GZIA 2230 HPX - Page 1
Forum section: electronics / repair

author: xavlaur
author_rank: Contributor
timestamp: November 01, 2021, 03:45:25 pm
content: Hello !Does anyone have the schematic / service manual from Ground Zero GZIA 2230 HPX?Thanks

author: xavlaur
author_rank: Contributor
timestamp: November 06, 2021, 11:34:47 am
content: Hello !I have a car amp whose scheme I can't find Ground Zero GZIA 2230 HPX but we can talk about a similar scheme - gzha-2350x.This amplifier I suspect has a short or poor insulation in the power supply transformer because it has a very high idle current (6A).FPQ 50N60 were tested, they had 1.5 V on low - direct polarization, I exchanged them with new ones, as well, high consumption without any load. The load is due to the low insulation of the source transformer.The amplifier works perfectly fed separately differentially directly on capacitors.Rectifier diodes are ok. With them removed, there is still a huge idle current consumed by the switching source. FPQ 50N60 is constantly incing.On electrolytes there is a rectified voltage (the amplifier is powered by 2x12V / 50W in parallel which lights up 75% - so 75 W, so it would be a current of about 6A) but if it is supplied at 12 V directly, the transformer heats up and emits smoke.I see no other load except the transformer which has a few turns on each winding.In the primary it has 0.6 ohms.In the secondary it has 0.2 ohms.I am interested in who has the expertise on these transformers if the resistors are ok at 0.2 and 0.6 ohm.It probably needs to be rewound.I see no other explanation for such a big idle current with impeccable final stage.Thanks