hybridfree/eevblog-posts huggingface dataset:
Oscilloscope HP Agilent 54600A 100 MHz (1991) trigger issue FIXED - Page 1
Forum section: electronics / repair

author: Spectrum
author_rank: Regular Contributor
timestamp: November 27, 2020, 10:22:50 am
content: I have this scope, it seems work well, all funtions ok, but the trigger DIDN'T work in any source or coupling.I replaced U9 (AD9300KP a 20 pin PLCC), placed on the mother board behind the inputs, after verifying that it was powered. Now the tool works fine.The IC was bought from China and was a stock fund (1997).I do not know if it is the correct way to post a fixed issue, if is not excuse me and tell me how.

author: shakalnokturn
author_rank: Super Contributor
timestamp: November 27, 2020, 02:26:24 pm
content: Not sure there is a specific way to post fixed issues but it's good that you did it any how.There are so many members cluttering-up with badly formulated questions, useless multiple subjects on the exact same repair and those that get advice and may (or not) succeed thanks to it but never even bother to come back and write a conclusion...

author: Spectrum
author_rank: Regular Contributor
timestamp: November 28, 2020, 08:19:04 am
content: I hope this post results in a search (here or Google) and be useful to someone.What you write is unfortunately common to all forums
Oscilloscope - Leader LBO 513A Half Screen - Page 1
Forum section: electronics / repair

author: Kolvir
author_rank: Newbie
timestamp: February 08, 2020, 06:38:53 pm
content: I was given the scope, but it suffered so damage in shipping. The CRT only shows on the left side. The photo is supposed to be a square wave from the test terminal. Does anyone have suggestions of where I should start looking to fix this? I have the service manual. This is my first scope, so I don't know where to start. It worked fine before shipping..

author: torquil
author_rank: Regular Contributor
timestamp: February 09, 2020, 07:24:01 am
content: Does it have wires going to horizontal deflection plates in the CRT? And if so, is one of them loose?

author: Kolvir
author_rank: Newbie
timestamp: February 11, 2020, 12:10:11 am
content: I'm not sure, I am trying to tack it down, but haven't been able to find that exactly. I've checked all of the wires coming out of the CRT and they appear connected correctly. I think the unit took a blow to the side during shipping and am afraid there might be a broken solder joint or trace. Someone told me to get out the magnifying glass, but I don't have a lot of experience at this and am not sure I will spot the break.

author: David Hess
author_rank: Super Contributor
timestamp: February 12, 2020, 11:25:33 pm
content: My first guess would also be that one of the horizontal deflection leads fell off.Are the horizontal and vertical calibration correct?

author: madao
author_rank: Frequent Contributor
timestamp: February 15, 2020, 05:12:50 am
content: a dumb ask: did you turn horz position pots?
Oscilloscope service manual (schematic) Lvyang YB4325 - Page 1
Forum section: electronics / repair

author: jeffnogdeveloper
author_rank: Newbie
timestamp: December 29, 2023, 02:18:25 am
content: Hello friends.I'm new to the forum, so forgive me if I'm doing something wrong.I'm looking for the Lvyang YB4325 oscilloscope schematic. Here in Brazil it is the Minipa MO-1227. I also found it as GW GOS-626G. (see attachment photo)My device has a horizontal problem: there is only an image from the center to the right. I measured the voltages at the source, I also measured the output transistors, I changed them to test... but the problem remains.I noticed that the voltage regulators get very hot.So having the schematic would help me a lot in identifying the problem.Thanks.
Oscilloscope takes long time to turn on - Page 1
Forum section: electronics / repair

author: Warsp
author_rank: Contributor
timestamp: August 15, 2022, 09:40:00 pm
content: I recently got an old Hameg analog oscilloscope off of ebay and it takes over 30 seconds to show a trace. I know the CRTs need to heat up a bit before they begin to work but from what I've seen on youtube, I don't think it should take this long. After it heats up it works quite well but is this long startup time due to it just being really old or should I be concerned about this. I know I should probably measure the heater voltage on the CRT, but that would require me to have to reseat the board connectors due to them being really loose and possibly shorting something to -1900V. Thanks.

author: Zenith
author_rank: Frequent Contributor
timestamp: August 15, 2022, 10:59:41 pm
content: 30 seconds sounds about right. My 20MHz (1990) analogue scope seems to take a long time to warm up. I'm sure it used to be quicker, but I haven't timed it so that's just a vague impression.Don't try measuring the heater voltage until you've had a good look at the service manual and you are certain there'll be no unpleasant surprises. There's probably nothing wrong with it anyway.

author: mag_therm
author_rank: Frequent Contributor
timestamp: August 15, 2022, 11:19:37 pm
content: I suggest you wait 15 minutes then check it has usable brightness range in auto trigger on the fastest time base sweep.The old Eico here is a bit faster than that to show a trace.Some of the old tubes eg rectifier, had internal controlled filament heating to give time for other parts to stabilizeCan you obtain a manual?

author: Warsp
author_rank: Contributor
timestamp: August 15, 2022, 11:54:26 pm
content: Glad to know that the longer startup time on the oscilloscope is not unusual. Besides taking a while to show a trace, the scope works pretty well and the trace brightness is pretty good. Thanks.
Oscilloscope UNI-T model UPO2102CS gets blocked in ARMED Trigger - Page 1
Forum section: electronics / repair

author: Android8888
author_rank: Newbie
timestamp: May 28, 2025, 09:01:58 pm
content: Hello everyone.I'm from Portugal so I apologize for my English.I would like to ask for help with my UNI-T model UPO2102CS oscilloscope which I used just a couple of times and now is having a glitch.While I was trying to use the oscilloscope it started in TRIGERED mode but when I click on any button, it switched to ARMED mode and then it gets blocked. It doesn't show anything on the screen and it only responds when I restart it again, but stays in the same ARMED state.I searched in the forum and found that most likely it is a firmware problem, because I found some people here experiencing the same problem with other models and solved it by reinstalling the firmware.I searched in UNI-T website and I couldn't find the firmware for this model UPO2102CS. It seems the model is descontinued and they don't provide the firmware anymore.Now I'm frustrated and sad because I spent many hours trying to discover how can I solve the problem.I would appreciate it if someone could help.Thanks in advance.
Oscilloscopio 3" monotraccia TR7 - Page 1
Forum section: electronics / repair

author: bengata
author_rank: Contributor
timestamp: November 03, 2023, 03:11:59 pm
content: Hello, I am looking for service documentation for the oscilloscope monotraccia TR7https://www.radiomuseum.org/r/sre_oscilloscopio_monotracci.html

author: picburner
author_rank: Frequent Contributor
timestamp: November 03, 2023, 07:46:44 pm
content: You won't find a real manual for that instrument because it was part of a correspondence school course. The school was called "Scuola Radio Elettra" and the course dates back to 1980.The only thing you can find are the instructions for building it and schematics as per thislink. (he's a guy who sells it on eBay)Of course everything is written in Italian.
Osciloscope HP infiniium 54815A progam Ver: 3.5 and drivers - Page 1
Forum section: electronics / repair

author: radoslaw
author_rank: Newbie
timestamp: February 01, 2018, 12:02:46 pm
content: Hello.I received oscilloscopes for repair.infiniium configuration:mobo: AMI ATLAS IIICPU: AMD K6 200MHz64MB SIMM RAMand four expansion cards:ethernet isa cardE2072 isa comunication card probably GPIBPCI card with alteraPCI card with IDE AND FLOPY socket main chip F6550 BDiagnosis:- Dead HDD- 3V baterry is also dead.After adding external cr2023 and replacing HDD.I was able to install Win98.Now I`m loking for program and drivers.I found information that it should be here:ftp://ftp.keysight.com/callpub3/ddt/scope/548xx/Upg_Rec/But the catalogs are empty.Will there be any good man who has files from these catalogs somewhere and would be willing to share them with me?Sorry for my bad English.

author: Daxxin
author_rank: Regular Contributor
timestamp: February 03, 2018, 04:17:35 pm
content: look at this if fit for youhttp://pdub.net/projects/agilent-recovery-cd/

author: abeasley
author_rank: Contributor
timestamp: March 09, 2018, 08:36:49 pm
content: I've run into a similar problem. I've been searching high and low for the software but the closest I found was an empty folder on Agilent's FTP site. I'm not sure if that link will work since it was for the 54824A and possibly different hardware. Mine is a 54815A with a US381xxxxx serial.Does anyone happen to have a backup of HP's software somewhere?

author: TRN
author_rank: Unknown
timestamp: March 29, 2018, 11:25:29 am
content: If you send a nice email to the Keysight support team they will upload the software for you on the FTP.It will stay there for +/- 7 days, and then it will be deleted

author: Tony_G
author_rank: Super Contributor
timestamp: March 29, 2018, 03:03:49 pm
content: I have the software hosted on my OneDrive herehttps://1drv.ms/f/s!Amqar8_XQ9Uzj6YhN1xHdM8tQdKMOA- Documentation is in the PDF in that folder.TonyG

author: lyncse
author_rank: Newbie
timestamp: September 09, 2018, 12:35:18 pm
content: ... necrobumping this threadI think it may be useful to point to the fact that ancient BIOS on these m/b has a network boot capability which frees end user from need of gutting scope on every backup/reinstallation or the need of purchase parallel-port CD-ROM. Short explanation for the modding procedure is available by a link below. Also please note that during standalone upgrades which are meant to be hosted on C: instead of zip-drive, the location of the upgrade data should be equal to c:\scope\upgrade\scope\temp\, otherwise the upgrade will failpermanently.http://xdel.ru/downloads/548xx/netboot-mod/mod-52820a.txt

author: pawlowski
author_rank: Newbie
timestamp: May 28, 2019, 10:05:49 pm
content: hi, does v3.5 work also for older AMI (not fic) motherboards?

author: Jacek
author_rank: Newbie
timestamp: May 31, 2019, 10:26:29 pm
content: Quote from: pawlowski on May 28, 2019, 10:05:49 pmProbably not, this is the reason that he sold the oscilloscope on Allegro.
Osciloscope screen flickering - Page 1
Forum section: electronics / repair

author: Dom324
author_rank: Newbie
timestamp: March 23, 2021, 08:37:00 pm
content: Hi,I have borrowed an osciloscope (DS1102E) from school - first few months it worked wonderfully, then I didn´t use it for like a month or two. After that I plugged it in and started probing with it - the scope works fine, except that the screen flickers quite badly (I´m gonna upload a video to YouTube and post it there later).Is this like an common issue? Is there something I can do to fix it? Could flashing firmware resolve this issue (the scope is from school, so I don´t want to mess with it unnecessarily)?Thanks for any help.

author: bob91343
author_rank: Super Contributor
timestamp: March 23, 2021, 10:01:20 pm
content: Don't mess with it. Return it and explain. Perhaps they can have it fixed and lend it to you again. Otherwise you are setting yourself up for trouble and expense should they blame you for the problem.

author: WattsThat
author_rank: Frequent Contributor
timestamp: March 24, 2021, 12:19:10 am
content: Use the quick start guide below and use the AUTO setup while on the internal probe calibration source. If autoset doesn’t reset the problem take it back to school and explain what happened.https://beyondmeasure.rigoltech.com/acton/attachment/1579/f-015f/0/-/-/-/-/file.pdf
OSS TEAM T210 soldering station repair help me - Page 1
Forum section: electronics / repair

author: michal.marta
author_rank: Newbie
timestamp: March 23, 2024, 06:48:58 pm
content: I need help with the T210 station, my MOS has burned out..can't see the part number anymore does anyone have the same station and looked what is the MOSFET name number?when I set the tip to 300 celsius, it is still cold..I attach a photo

author: floobydust
author_rank: Super Contributor
timestamp: March 23, 2024, 07:09:41 pm
content: Welcome to the forumsI would first resolder it, one side the pins look up. Usually a 30V P-ch MOSFET used in laptops. Most common is TPC8107 or TPC8111 orAO4407has a bit higher RDSON

author: michal.marta
author_rank: Newbie
timestamp: March 23, 2024, 10:31:40 pm
content: Mosfet I found a piece of H&M on AliExpress H&M HM4409

author: floobydust
author_rank: Super Contributor
timestamp: March 24, 2024, 02:41:57 am
content: Oh it's burnt up, shorted heater or bad socket or crappy part. You would think the mosfet can outmuscle the PSU.AO4409looks good too.
OSS TEAM T210 soldering station repair help - Page 1
Forum section: electronics / repair

author: realfran
author_rank: Regular Contributor
timestamp: June 28, 2022, 12:12:52 pm
content: Hello, I got one OSS TEAM T210 soldering station when am in sleep mod the buzzer starts sounding continual, if I take the tip stop sound, the tip does not eat (I test two different of them).Please some suggestions to test the wiring of the handle and the tips?I put some pictures to give a better idea.

author: thm_w
author_rank: Super Contributor
timestamp: June 28, 2022, 09:32:27 pm
content: SE would imply sensor error, in that its seeing an open circuit on the thermocouple or some unexpected voltage.Unplug the power, open it up, and measure from the inside to the handle, see if the thermocouple is connected as expected.Small chance some setting might have been screwed up (uV/C setting?) but seems unlikely that would trigger an error.Unplug the tip and measure its resistance, make sure heater is intact.http://adgd.ru/2021/01/04/jbc-soldering-cartridges-pinouts/

author: realfran
author_rank: Regular Contributor
timestamp: June 30, 2022, 05:58:44 pm
content: I test two different tips and do the same, when is on sleep mode the handle on the holder and the buzzer go on continually, I ordered the new handle and tips.
Motherboard no Image - Page 1
Forum section: electronics / repair

author: 2X
author_rank: Frequent Contributor
timestamp: August 01, 2023, 05:02:18 am
content: Hello,I have the below problem. I open the PC and it starts (CPU fan is working) but I have no image at all (not from the external VGA and neither from the on board VGA). Near to the bios chip there was some blown capacitors so I supose that something was happend with the voltage of the bios chip and the bios program corrupted or am I totally wrong? I replaced the "1" CPU with the "2" CPU and no image again. Also, I measured the CPU supply cable and it has 11,8Volt, but the strange thing is that both CPUs "1" & "2" are absolutely cold and the CPU fan spins (also the VGA chip is cold). All these symptoms are not bios (I can't find this bios... does anyone have it?)?

author: coromonadalix
author_rank: Super Contributor
timestamp: August 01, 2023, 11:03:00 am
content: 1st give us the motherboard specs model number ...do you connect all the power supply lines, at least you need 2 connectors 1 for the cpu the other for the board ...is your psu okay ?

author: 2X
author_rank: Frequent Contributor
timestamp: August 01, 2023, 05:10:29 pm
content: I measured on the motherboard 3,3V, 5V, 1,2V, 12V.

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 01, 2023, 09:48:18 pm
content: Quote from: 2X on August 01, 2023, 05:02:18 amIf you are lucky then yes.But I don't see a bios chip on the MB photo at all.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 01, 2023, 10:57:59 pm
content: mmm they look like kontron 478 boards or ibase 478 .....Kontron pcg820seems a variant of this onebut the photo show the bios socket on solder side ??https://met8257.blogspot.com/2020/04/sbc-kontron-sbc-vga-single-lan-pcg820.htmlhttp://mediaserver.voxtechnologies.com/FileCache/Kontron-PCG-820-D-1341847773S.pdfwelllyou had your answer already written on the pcbTEAN TN2 94V0now the Hard part is to find some bios ?? and conflicting infos, some sites say socket 370 ?? and some the socket 478https://www.ebay.ie/itm/223644984142?https://www.ebay.ie/itm/255981822001?https://www.ebay.ie/itm/313961503070?https://www.ebay.ie/itm/385139821903?https://www.ebay.ca/itm/164288627254?https://www.ebay.ca/itm/303698890084?did not found anything but fakes links or else, you may need to buy another one?

author: 2X
author_rank: Frequent Contributor
timestamp: August 02, 2023, 05:29:57 am
content: Here you can see it. I upload wrond picture in my first post. I apologise.
Outer rubber sheath pulled back on my laptop charger. Tips for repair? - Page 1
Forum section: electronics / repair

author: Mighty Burger
author_rank: Regular Contributor
timestamp: September 22, 2022, 06:46:54 pm
content: A little over a year ago I purchased an XPS 9500 laptop from Dell. I've enjoyed the laptop and I think I made a good choice at the time. The charger isn't doing so well though. Still works but it looks like it's in the early stages of falling apart, since the outer rubber sheath pulled out from under the strain relief. Any tips for repairing this or should I just get a new one?Thanks!

author: Gyro
author_rank: Super Contributor
timestamp: September 23, 2022, 05:22:15 pm
content: Heatshrink sleeving usually works, depending on how large the DC jack is. You need to use adhesive lined, with at least a 3:1 shrink ratio (I think you can get 4:1). Use the smallest diameter that you can persuade over the DC jack - you can achieve abrieffurther expansion by stretching sleeving over the jaws of some round nose pliers.Shrink the sleeving over both the strain relief and the cable outer - if the bit over the cable doesn't shrink enough, you can squeeze the sleeving flat at each side while still hot. The result will provide both mechanical support for the weakened cable and some protection against further pulling.

author: themadhippy
author_rank: Super Contributor
timestamp: September 23, 2022, 06:39:49 pm
content: sugru, mold it around the area you want repaired and leave it to set
Output amplifier Darlington replacement - Page 1
Forum section: electronics / repair

author: Jester
author_rank: Frequent Contributor
timestamp: April 16, 2020, 03:23:45 pm
content: I'm repairing this 10VA output amplifier circa 80's?The amplifier drives a transformer and operates in the 50-500 Hz rangeThe Q7 output 2N6385 has failed (TO-3) package I normally order from Digi-Key, or Mouser however this part is not stocked, and the non stocked part is priced at $65 a pop minimum 100, not going there.The NTE245 looks like a good substitute, however neither Digi-Key or Mouser have that either.Any suggestions for a viable substitute from D-gi-Key or Mouser?[ Specified attachment is not available ]

author: coromonadalix
author_rank: Super Contributor
timestamp: April 16, 2020, 03:35:33 pm
content: hum not sure maybe mje15023, mje125024, mje15025 could do ??

author: andy3055
author_rank: Super Contributor
timestamp: April 16, 2020, 03:53:10 pm
content: Try this:https://www.newark.com/nte-electronics/2n6385/darlington-transistor-npn-80v/dp/33C8325?CMP=KNC-GUSA-GEN-KWL-DSA-Abandoned-Cart-NTE-ELECTRONICS&mckv=swNtZnV4X_dc|pcrid|363776851436|plid||kword||match|b|slid||product||pgrid|17246335221|ptaid|aud-126792145221:dsa-288097058865|&gclid=EAIaIQobChMIsMTv26bt6AIVBhatBh20MwueEAAYASAAEgJFDfD_BwE

author: shakalnokturn
author_rank: Super Contributor
timestamp: April 16, 2020, 09:25:41 pm
content: Not TO3 encapsulated but this topic could be of interest to you:https://www.eevblog.com/forum/repair/repair-of-audio-amp-using-sanken-sap15n-sap15p-output-transistors-fixed/In the metal can world the BDX85B (/C) and BDX86B (/C) look close enough to what you need, I don't know about price and availability though.

author: fzabkar
author_rank: Super Contributor
timestamp: April 16, 2020, 10:17:29 pm
content: https://www.newark.com/nte-electronics/2n6385/darlington-transistor-npn-80v/dp/33C8325
Output recapping of switching PSU - Which cap to use - Page 1
Forum section: electronics / repair

author: ppTRN
author_rank: Regular Contributor
timestamp: May 30, 2023, 05:07:47 pm
content: Hi, I repaired a board that had a fault in the supply section. Turned out that it was just the output capacitors, a few 100uF and 220uF, 50V rated. I replaced them with what I had at home, same values but 63V rated. All removed caps' capacity measured just fine, but i was not able to measure ESR (i do not hav an ESR meter).There are other board with the same problem, so i was wondering if you guys can suggest me a particular brand of capacitor particularely suitable for the job, something dependable. There is also the input capacitors, some 330uF 450V beasts. I did not replace them and the board works just fine. Is it suggested to replace them too? If so, are there any trusted brands?PS: all caps are electrolitic.Thank you!

author: mariush
author_rank: Super Contributor
timestamp: May 30, 2023, 06:10:16 pm
content: On the capacitors you replaced, you will see the capacitance, the voltage rating and a code for the series. If you want to, you can then find the datasheet for that series, and extract the important information like current ripple and impedance @ 100kHz for that particular capacitor (varies with size, with capacitance and voltage rating).So once you know these, you can pick something compatible, with equal or a bit lower impedance and same or a higher current ripple value.Of course, you'll also have to measure the diameter of the capacitor and the spacing between the leads, and you need to figure how high you can go, don't want to pick some capacitors that are too tall and maybe hit the fan or some other obstructions.Nichicon, United Chemicon, Rubycon, Panasonic these are big brands with good reputation.Wurth, Samxon are less known but ok... Kemet is less known in power supplies but depending on series it could be fine.. Aishi is acceptable, i wouldn't mind using it for high voltage capacitors, but you should be able to get from the previously mentioned manufacturers easily.Samwha may be fine, but I've replaced a lot of them in lcd monitor power supplies I prefer not to use them... but they could be good now (though it could be they were misused, in an enclosed hot area, not necessarily the fault of the capacitors)Based on your flag, I'd suggest checking out tme.eu , here's 100uF and 220uF 50v, ordered by stock amount :long linkFrom that list Panasonic FR , FM 100/50 and Samxon GF would probably be fine. Panasonic FC series is low impedance but a bit on the high side, it would probably work, but FM and FR is better.

author: ppTRN
author_rank: Regular Contributor
timestamp: May 30, 2023, 06:57:54 pm
content: Thank you, i'll check the link

author: tunk
author_rank: Super Contributor
timestamp: May 30, 2023, 06:59:25 pm
content: This looks like an SMPS, so you probably want low ESR caps.
Output Transformer for an old Fender Amp - Page 1
Forum section: electronics / repair

author: Kilroyonguitar
author_rank: Newbie
timestamp: February 26, 2025, 05:45:36 pm
content: I bought this beautiful old 1963 Fender amp knowing it needed a lot of work. It has an output transformer in it but all the wires are cut and I'm not sure if it's the original crappy one just not taken out or it's a replacement that just wasn't soldered in before the previous owner passed. I took a bunch of ohm readings but to be honest I don't have a clue what they're really telling me. See Attached. Any advice appreciated.

author: benj38
author_rank: Frequent Contributor
timestamp: February 27, 2025, 08:52:53 pm
content: Your transformer is toast.

author: Sassy Taste
author_rank: Contributor
timestamp: February 28, 2025, 05:34:33 pm
content: NOTE: This message has been deleted by the forum moderator Simon for being against the forum rules and/or at the discretion of the moderator as being in the best interests of the forum community and the nature of the thread.If you believe this to be in error, please contact the moderator involved.An optional additional explanation is:

author: themadhippy
author_rank: Super Contributor
timestamp: February 28, 2025, 05:52:45 pm
content: QuoteA 240w marantz stereo amp is a totally different beasty to a 1963 fender guitar amp.QuoteTheirs certainly no ic's inside em,even transistors and rectifier diodes are a bit to modern for them

author: Xena E
author_rank: Frequent Contributor
timestamp: February 28, 2025, 06:00:01 pm
content: Quote from: themadhippy on February 28, 2025, 05:52:45 pmDont waste your time, 'Sasy Taste' has posted 16 times within a day, all 100% bullshit.Some kind of spammer or bot?Regards,X

author: floobydust
author_rank: Super Contributor
timestamp: February 28, 2025, 07:07:42 pm
content: Kilroyonguitar, there are many manufacturers of replacement (guitar) tube amp transformers. 125A6A used in many Fender models but it's 4 ohm. Just buy a new one. Shipping costs are significant.Edcor USAlow pricesHammond Mfg.1750Jelectro-harmonixSowter Transformers UKMarshall newer models added a couple HV diodes to limit the O/P transformer voltage, which can go very high if the loudspeaker gets disconnected/open-circuit or you just push the amp past the overload limits. I add those to old amps.

author: themadhippy
author_rank: Super Contributor
timestamp: February 28, 2025, 08:01:50 pm
content: Quote
Output Voltage minimal Changing - Flexiforce Sensor Issue - Page 1
Forum section: electronics / repair

author: Rocky Richi
author_rank: Newbie
timestamp: April 02, 2025, 03:41:05 am
content: Hello everyone,I'm working on an electronics project that uses a flexi force sensor A201 , INA333 instrumentation amplifier and esp32 module ,and I've simulated the circuit using lt1167(in place of ina333), changing the resistance value(in place of sensor) and used behavioural voltage source (in place of adc value conversion on esp32) in LT spice.However, I'm running into an issue:when I apply force to the sensor, I observe minimal step variation in mV range in the LT1167's output voltage and no or minimal step variation on bv source valuesWhat I Have Tried So Far :1.Tried to invoke the ina333 spice models but simulation was not behaving properly.2. hence used lt1167 built in library ina which is present on ltspice platform.3. I updated circuit to resolve the issue by adding capacitors to ensure the noise is the problem.4. Later I checked for the different voltage levels but no change.5. Later I thought voltage divider may be problem and hence removed it but no effects.6. also changed r2 value and gain r3 value but it just increased the output voltage swing and bv source value.7.Also employed the opamp to provide the stable buffer to ref pin.Are there any circuit modifications or additional components that could help enhance the sensitivity of the circuit?Any suggestions would be greatly appreciated !

author: Rocky Richi
author_rank: Newbie
timestamp: April 02, 2025, 12:14:45 pm
content: Please provide suggestions for my circuit since I am stuck with past three days

author: Poroit
author_rank: Frequent Contributor
timestamp: April 03, 2025, 03:43:46 am
content: Is this a Dynamic force sensor ?How are you applying force to the sensor?Have you tried the "Recommended Circuit" to prove that the sensor is OK?
Outside unit of Tesa Weather Station Pro ws1151 - Page 1
Forum section: electronics / repair

author: khos8
author_rank: Newbie
timestamp: December 05, 2024, 08:15:05 am
content: Outside unit of Tesa Weather Station Pro ws1151 stopped working. As in no temperature and humidity reading on the display. Main unit also does not pick up anything from the outside.There are some white-ish deposits on the PCB see - photos. It seems like it’s caked onto the board. Maybe condensation that got dried up after years of being outside?Pointers on what to check will be appreciated. I have some (far from great though) soldering skills and with enough luck may be able to replace a capacitor or similar.Figured worth a shot before chucking into a landfill.Thanks!

author: Poroit
author_rank: Frequent Contributor
timestamp: December 06, 2024, 08:45:36 am
content: G'day khos,It looks likes water damage. Do you live near the coast?https://hzo.com/blog/corrosion-water-damage-electronicsWas there a Desiccant pack inside the instrument?

author: khos8
author_rank: Newbie
timestamp: December 06, 2024, 09:02:07 am
content: Thanks for the link.Good call.Yeah, it's pretty humid here throughout the year.You reckon it's a goner? No reason to try and salvage?

author: floobydust
author_rank: Super Contributor
timestamp: December 06, 2024, 07:10:15 pm
content: The board is dirty in critical areas, it needs to be cleaned - but without splashing anything on the humidity sensor and wrecking it!I think it's soldering flux, not sure if water-soluble but I would first use q-tips and IPA to spot clean a few places.The crystal leads on the top are filthy, there is black creep corrosion on the LCD display terminals too, and the batteries look to have taken a piss at some point.Normally I would remove the humidity sensor and soak the board in hot dishsoapy water and use an old toothbrush to scrub it. If the contamination is not water soluble, like the battery corrosion I'll first use vinegar (on a q-tip) to get that off, then rinse and dry the board.
oven oscillator 119-1576-01 - Page 1
Forum section: electronics / repair

author: hnjmkl
author_rank: Regular Contributor
timestamp: February 19, 2021, 09:41:37 pm
content: I would like to use this new oscillator, it is mounted on the tek 494, I should know on which lugs the voltages + 5 + 15- + 17 .[ Attachment Invalid Or Does Not Exist ]
Over Voltage Isolatation Transformer ? - Page 1
Forum section: electronics / repair

author: Randall
author_rank: Newbie
timestamp: October 06, 2022, 05:37:38 pm
content: Hey FolksIs this a Nubie or a repair question ?I'm a bit spooked by this issue. I have Hospital Grade Iso Transformer which gives over 130 volts without a load.My Home voltage here in Michigan is near 123 volts or so, and this Iso Transformer when connected delivers over 130 volts a bit.I place this in repairs because It just doesn't seem right and I'm fearful to plug something into it.What don't I understand ?See Photo.

author: bdunham7
author_rank: Super Contributor
timestamp: October 06, 2022, 05:42:49 pm
content: Quote from: Randall on October 06, 2022, 05:37:38 pmThere's absolutely nothing wrong. What you haven't factored in is that the transformer has impedance(s) that would always result in lower voltages under any load if it were wound 1:1. So what they do is wind it as a small step-up (perhaps 1:1.05) with impedances low enough to limit the voltage drop to something like 10% under load. So at no load it will be +5%, at half-load it will be nominal and at full load it will be -5%. And that's all within tolerances and a very common feature of isolation transformers.

author: jdragoset
author_rank: Frequent Contributor
timestamp: October 06, 2022, 06:43:26 pm
content: Test to make sure the output neutral is not connected to earth ground.An ohmmeter with no power applied will tell.

author: Randall
author_rank: Newbie
timestamp: October 06, 2022, 11:44:55 pm
content: THx !My paranoia is put to rest !Yes, the neutral is disconnected from Mother Earth .... !
Overheating Diode in Power Supply with TOPSwitch  - Page 1
Forum section: electronics / repair

author: 2X
author_rank: Frequent Contributor
timestamp: January 30, 2024, 08:27:00 pm
content: Hello,I have a power supply where on part of it has an SMPS trasformer with a TOPSwitch (TOP201YAI). The diode (D88) and the TOPSwitch were shorted. I replaced them but again the diode and the TOPSwitch were shorted. I used a variac with 36Vrms as a source instead of the mains (230Vrms) and with a thermal camera I saw that the diode (D88) in 5 sec reachs 90Celcious and if I don't cut the supply the temperature will continue to increase. I disconnected the diode and soldered cables on PCB in order to measure the current that flows through the diode and the current it just 55mADC. I can't understand at all the reason that this diode is overheating. Also, when I disconnect the TOPSwitch the diode don't overheat. I replaced the TOPSwitch with a brand new (TOP201YN - the final letters of the part number was not exaclty the same) and the same thing again. I made a schematic design and I can't understand what causes the overheating of the diode.At the picture with the cells are the measurements (with KEYSIGHT U1733C) of the SMPS transformer with all possible combinations between each pin.

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 30, 2024, 08:32:06 pm
content: 1N4007 is too slow for 100KHz, was it the original part?I've seen some schematics using a 1n4148 (1ns switching time).I don't think the meter measures current very well at 100KHz?Make sure the capacitors are not shorted, sometimes they show ok when measuring wih the DMM but conducts under higher voltages, I'd test them under 12V.

author: 2X
author_rank: Frequent Contributor
timestamp: January 30, 2024, 08:42:17 pm
content: I am not sure that the 1N4007 is the original component. Because the 1N4007 isn't ultra fast you believe is a reason for such overheating?

author: DavidAlfa
author_rank: Super Contributor
timestamp: January 30, 2024, 08:51:47 pm
content: Absolutely, you will never see a 1n4007 in the high-speed section of switching power supplies!Every diode has a turn-off time, when the input voltage goes negative the current will flow backwards for a small time.For the 1N4007 it's about 1.5us, this is not a problem at 100-120Hz, but at 100KHz it will:100K *1.5us = 150ms!Power diodes meant for high speed power switching are much faster, for example the FR302 has 150ns switching time.Try a 1n4148, or anything fast.

author: fant
author_rank: Contributor
timestamp: January 30, 2024, 10:58:43 pm
content: Try with UF4007, superfast and with all the other characteristics similar

author: 2X
author_rank: Frequent Contributor
timestamp: March 26, 2024, 11:11:35 pm
content: Finally the problem was the speed of the diode as you all said. I placed the UF4007 and works fine. Thanks all of you for the replies and help.
Overlays the strips from the matrix in the laptop  - Page 1
Forum section: electronics / repair

author: AT-12
author_rank: Newbie
timestamp: October 10, 2024, 08:08:23 pm
content: HelloI need help repairing the tape from the matrix in my laptope msi titan pro gt73 6rfI managed to locate the fault, the tape visible in the photos is to blameUnfortunately, I have no other idea than to replace the entire sensor, everything is permanently solderedIs there any way to resuscitate such a tape?

author: tom66
author_rank: Super Contributor
timestamp: October 10, 2024, 08:28:30 pm
content: For an average person, no. That screen is dead. You would need to remove that connection and replace it, it has thousands of microscopic connections that drive the columns on the LCD panel.It is possible for some factories and workshops to repair this, I think it is done in some Chinese phone repair shops now. But the equipment is too expensive for a one-off repair.You need to buy a new LCD panel.

author: AT-12
author_rank: Newbie
timestamp: October 10, 2024, 08:34:03 pm
content: Thank you very much for your helpAnd you know, the worst scene has come true
OWON 14bit XDS3202A Oscilloscope PSU repair - Page 1
Forum section: electronics / repair

author: patrik96
author_rank: Contributor
timestamp: April 19, 2023, 05:25:26 am
content: HI, May someone could help,I have a XDS3202 (14bit) scope, unfortuneately under a measurement the GND aligator clips uncained and touch a -70V rail, and after my scope semi brick,It mean the screen, and all fuction working (the relay switch, the DMA work) except no visualable signal on the screen, (either the AWG not give any signal out) If I put direct input on the ADC IC it has visuable signal,My investigation is may the negative -xxV power suply faild but no schematic found it.The new main panel is almost 800€ what is not a option for repair,If someone know the measure point and voltage it also could help a lot.A schematic could help
Owon DS7104 (TDS7104) oscilloscope firmware needed. - Page 1
Forum section: electronics / repair

author: rubennss
author_rank: Contributor
timestamp: October 03, 2024, 03:34:28 am
content: The oscilloscope stops at the start screen and nothing further happens.I checked the voltage converters - they all seem to work properly.According to the owner, the oscilloscope was unused for two years, when trying to turn it on, it stops at the start screen.No signs of flooding, the components are not heated, the equipment has been used very little.Everything points to a firmware failure.Do any of you have firmware for this oscilloscope?I have written to the manufacturer and several vendors around the world, NO ONE has responded.I could not find firmware for this model on the manufacturer's website.
Owon DS7104 oscilloscope, help in identifying the IC  in the voltage converter. - Page 1
Forum section: electronics / repair

author: rubennss
author_rank: Contributor
timestamp: September 25, 2024, 05:01:11 pm
content: I own a defective Owon DS7104 oscilloscope.After turning it on, the logo appears on the screen and further it does not start. The symptom may suggest a dumped firmware but not in this case.I couldn't find the schematic, so I'm setting up this post.I made some voltage measurements of the inverters and one of them does not give any voltage ( it is the one with IC U99, choke L8).Measuring the resistance on choke L8 to ground I have a full short circuit ( no wonder there is no voltage on it).Before I do a short-circuit test and use a thermal camera, I would like to find the datasheet of the IC (U99, VUBI TI56 ( or T156) SO5F).I can't find what kind of IC it is.I don't count on finding a schematic of an oscilloscope, maybe someone has a schematic of some inverter in which such an IC works?I know that I can look for the faulty component in many ways, but before I start, I would like to have a datasheet of this chip.

author: fzabkar
author_rank: Super Contributor
timestamp: September 25, 2024, 05:52:11 pm
content: VUBI = TLV62130https://www.ti.com/packaging/en/docs/partlookup.tsp?partmarking=vubihttp://markingcodes.com/search/c/vubihttps://ipv4.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+vubi+converterhttps://www.ti.com/lit/gpn/TLV62130(datasheet)

author: rubennss
author_rank: Contributor
timestamp: September 25, 2024, 06:42:57 pm
content: fzabkar:Thank you very much for your help, In our country there is a saying - a person is born stupid and stupid dies ( talking about me).Links to search for items - will be useful in the future.

author: gupa
author_rank: Newbie
timestamp: September 25, 2024, 07:04:39 pm
content: If I may tell, the R454 is unglued?

author: rubennss
author_rank: Contributor
timestamp: September 29, 2024, 09:14:03 am
content: thank you for your responses,gupa: the resistor is not soldered correctly, but there is an electrical connection.After analyzing the data sheet, and the inverter circuit in this power branch, it turns out that it is a negative voltage inverter -5.6V DC, the circuit works correctly, and the short to ground on the choke is correct in this case.So everything points to a firmware failure in this oscilloscope.I need to start a separate topic, maybe someone has knowledge and experience on how to reload it.Thanks.
Owon DS8202 oscilloscope with frozen screen - Page 1
Forum section: electronics / repair

author: mooksmd
author_rank: Newbie
timestamp: December 24, 2023, 03:49:56 pm
content: This scope has worked fine for about a decade. Suddenly, the welcoming screen runs for about 5 seconds then freezes with vertical lines overlayingthe display. Never gets beyond the frozen screen.Any hope of fixing it ? I emailed Owon to ask for the firmware but never heard back.ThanksMike VE7SML

author: tunk
author_rank: Super Contributor
timestamp: December 24, 2023, 05:04:20 pm
content: Wouldn't really know. PSU problem? Open it and see if there's something obvious.

author: R-1125F
author_rank: Regular Contributor
timestamp: December 26, 2023, 09:59:16 pm
content: What have you tried so far? Did you measure power supply voltages?You could also try contacting Owon's operation in the US and see if they have a solution.USA Office -Lilliput Electronics (USA) Inc.130 Commerce Way,Walnut CA 91789 , USAContact : John Xu, or Joanna ChenT : +1.626.369.3088F : +1.626.369.3077E : sales@lilliputweb.netW :www.owonna.com

author: Zenith
author_rank: Frequent Contributor
timestamp: December 27, 2023, 01:41:11 pm
content: Do you mean an Owon SDS 8202?If so the service manual is available here.https://www.manualslib.com/manual/3010120/Owon-Sds-Series.html#product-SDS%20seriesThere's a fault finding flowchart but most of the resolutions are change the main board or change the LCD display.As said previously, with any faulty instrument, it's essential to make sure the power supply rails are at the correct voltage and free of ripple. If they are not any further investigation is a waste of time.Also as said previously, it's worth getting in touch with Owon North America. This may be a problem they've come across many times and there could be a simple solution, such as a factory reset procedure.

author: Sergey61
author_rank: Newbie
timestamp: May 07, 2024, 10:10:26 pm
content: считайте свой дамп, поделитесь. могу дать с своего 8102,но вам обязательно свой надо считать,там калибровки индивидуальные
OWON HDS272S oscilloscope function broken - Page 1
Forum section: electronics / repair

author: eurots2
author_rank: Newbie
timestamp: January 05, 2025, 02:27:09 pm
content: Hello everyone, i have an OWON HDS272S i bought for almost 2 months now. a week ago, i was troubleshooting an audio amplifier and accidentally connected the output of the amplifier to the output waveform generator of the OWON HDS272S, causing both oscilloscope and the waveform generator to broke(except the multimeter), the photo of the scope shows the aftermath where the output of the scope is not working. is it possible to be fixed?

author: Postal2
author_rank: Frequent Contributor
timestamp: January 05, 2025, 03:07:23 pm
content: It is necessary to check the power supply of the analog part, since the input amplifier produces a level beyond the screen.
Owon MSO8102T missing integrated circuit - Page 1
Forum section: electronics / repair

author: bengata
author_rank: Contributor
timestamp: September 09, 2023, 11:17:31 am
content: Hello, please help. I wonder if anyone knows what the schematic is U65

author: bengata
author_rank: Contributor
timestamp: September 11, 2023, 09:15:52 am
content: Please if someone can take a picture of it . Mainboard Owon mso 7102 , 8102 , 8202 .

author: bengata
author_rank: Contributor
timestamp: September 12, 2023, 02:06:02 pm
content: Missing IC is CH376S
Owon ODP3032 power supply problem - Page 1
Forum section: electronics / repair

author: Unixon
author_rank: Frequent Contributor
timestamp: October 28, 2019, 05:16:32 am
content: Hi, all.Unfortunately, the LCD backlight of my ODP3032 suddenly decided to quit. If I remember everything correctly, after working perfectly for few years the backlight recently just didn't came back after a few weeks long power off. PSU works fine, but I can barely see what's on display in reflected light. Does anybody know if this is a typical fault in this Owon PSU and is there a typical fix for that?Update:OK, I've opened up my unit and located LCD backlight driver on CPU board.LCD backlight is driven by constant current boost DC-DC converter G5126 by Global Mixed-mode Technology.Vin is at 5V, Vout is at maximum 28V, LED current is zero. CPU board ID is ODP3032_CPU_KZB_V1.7.Does anybody have schematic or service manual for this PSU?Looks like CPU enables backlight driver, but LCD has partially failed. Tried to reconnect backlight FFC few times, no luck.LCD type is ACX503AKP-7 338A37D, second number is different to ACX503AKP-7 339A41Dmentioned earlier in other threadhttps://www.eevblog.com/forum/testgear/odp3032-experience/Is it possible to get a replacement for this LCD?Update2:Looks like the LCD backlight is not the only problem, 2nd channel went 4.3% below set voltage in whole range, 1st channel looks fine.

author: Unixon
author_rank: Frequent Contributor
timestamp: November 06, 2019, 06:22:37 pm
content: Up!
OWON SDS 1104 power issue - Page 1
Forum section: electronics / repair

author: analog pro
author_rank: Newbie
timestamp: September 07, 2024, 06:49:49 pm
content: Hello everyone. My oscilloscope has the issue of not turning on. Anyone with its pcb layout or schematic diagram can send it to my email analogpro762@gmail.com. Thanks in advance

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: September 08, 2024, 06:44:39 am
content: Usually, schematics are not available for these scopes.Did you measure voltages on the power supply?

author: analog pro
author_rank: Newbie
timestamp: September 08, 2024, 09:22:29 am
content: yes. I measured the voltage and is as required, 5.7V.

author: analog pro
author_rank: Newbie
timestamp: September 08, 2024, 09:24:45 am
content: The issue is that the screen is not displaying anything. How do i fix it?

author: Gyro
author_rank: Super Contributor
timestamp: September 08, 2024, 01:16:05 pm
content: Try a performing a factory reset - no I don't know how to do it on that model, you'll need to find it in the manual or web search.

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: September 08, 2024, 06:04:51 pm
content: Does the owon use a backlit LCD? If so, check the backlight.Maybe wiggle the display connector around and see if that helps.If you have another oscilloscope, probe one of the display data lines and check for activity.
OWON SDS9302 CH1 & CH2 signal issues - Page 1
Forum section: electronics / repair

author: No.Mad
author_rank: Regular Contributor
timestamp: February 28, 2020, 07:57:53 pm
content: Hi everybody,recently I got my hands on OWON SDS9302V oscilloscope and after first power up i have behaviour as in attached photos. Happens all the time after minute or two (once it didn't for 10 min, I could do self calibration). Did anybody come across this problem?For interested what I managed to retrieve as once scope what functioning properly:Model: SDS9302VVer.: 1.5.1Checksum: C053DED0Square wave 5V, 1kHz, selfcalibration successful (once)I would appreciate any pointers where fault may live.Cheers!

author: shakalnokturn
author_rank: Super Contributor
timestamp: February 28, 2020, 11:52:26 pm
content: I'd check power is clean, just because that's where you're meant to start troubleshooting.Next I'd be looking for a BGA FPGA to push down on see if it gets you longer normal time.