hybridfree/eevblog-posts huggingface dataset:
Impact Sport Earmuff - Page 1
Forum section: electronics / repair

author: vidarr
author_rank: Frequent Contributor
timestamp: April 16, 2020, 07:27:34 pm
content: I have this "High Noise Reduction Rating Sound Amplification Electronic Shooting Earmuff" and one of the ears stopped working. No sound. It is the earmuff side without the driver board. After opening, I directly tested the speaker with a battery and it works. Then, I checked from the soldered leads on the driver board to check for a problem with the wire and the speaker still was working. So, it is not the speaker and it is not the wire from the driver board to the speaker.The driver board, battery connections, all the soldering looks in really great shape. So, if this is a bad component on the board, that's pretty much it for ever having sound in that ear again isn't it? I hope it isn't so. Any ideas I can try?Thank you!

author: vidarr
author_rank: Frequent Contributor
timestamp: April 17, 2020, 01:43:07 pm
content: Well, I found the problem. I couldn't see it even with glasses on. I was poking around at the connections with a DMM and heard the speaker start to crackle. I took the pic and zoomed in really close. There it was.Why would this happen though? And I am not the only one. There are many others out there with the same speaker being dead. Those people all ended up buying new earmuffs, so I don't know if it is exactly the same cause. But, still odd so many people with the same speaker dead. Maybe others will find this post when their speaker stops working and they do a search and see the likely cause. It is a very easy fix and will save $50 - $100 buying new earmuffs.Thanks.

author: vidarr
author_rank: Frequent Contributor
timestamp: April 17, 2020, 05:26:10 pm
content: This is for all the people that have the same problem with the speaker/mic failing on one side. It is NOT just the GND wire from the battery through the headset to the other side where it is soldered to the driver board. It was also the MIC wire. It was very poorly soldered and just came "undone". There is a soft gel that covers the MIC wires where they solder on; the wire seemed only to be held by the gel. The wire came lose just barely touching when re-assembling the headset.I know there are a lot of people out there with the same problem with the same set. Hope this helps someone.
impressive damage to washing machine control board - Page 1
Forum section: electronics / repair

author: JBeale
author_rank: Frequent Contributor
timestamp: August 05, 2019, 05:56:04 pm
content: Maybe this is the wrong place as I have no interest in repairing this. I was just impressed by the damage. Apparently some DIP-8 package (with only 7 pins) maybe part of a power supply, just exploded at power on, with subsequent damage elsewhere. It had been working OK for a year after we got it used. This is the control board from a Fisher & Paykel WL37T26DW2 96112-A washing machine.

author: Stray Electron
author_rank: Super Contributor
timestamp: August 05, 2019, 06:21:42 pm
content: What is that light blue staining in the upper FH corner of the first photo? It looks like water may have gotten on the board. I've had washing machine and dish washer control boards that got wet and shorted out but I've never seen such widely separated severe damage and so widely separated. What does F&P want for a new board?

author: Gyro
author_rank: Super Contributor
timestamp: August 05, 2019, 06:35:07 pm
content: That looks a bit like lightning damage to me.It's obviously cratered the top of the off-line switcher IC, but U701 looks like a pressure sensor - maybe providing a ground path via moisture in pipework? There seems to be a dotted curve of surface soot and damage between the two.

author: JBeale
author_rank: Frequent Contributor
timestamp: August 05, 2019, 07:04:54 pm
content: The light blue stuff is some kind of conformal glue layer. It was selectively applied over each of the larger power FETs on the board. Yes, there was some damage near the pressure sensor, among many other things. It does look pretty dramatic but there hasn't been any lighting storm recently, it just went bang when switched on that day. Possible some moisture got onto the board, although it appeared dry by the time I disassembled it. The machine is old enough that I only saw 3rd parties carrying parts, and I just decided to get a newer model.I did salvage the hot & cold water input manifold assembly including five 24V solenoid valves, in case some creative use for this presents itself.

author: amyk
author_rank: Super Contributor
timestamp: August 05, 2019, 08:13:47 pm
content: That's a TNYxxx single-chip SMPS controller. A quick search of the Internet reveals that they often blow up due to power surges. I suspect that's what happened here.

author: jleg
author_rank: Contributor
timestamp: August 07, 2019, 03:01:27 pm
content: Quote from: amyk on August 05, 2019, 08:13:47 pmyes, you even get "repair kits" on ebay for this type of damage, like "TNY278 plus 120ohms resistor", or the "LNK304GN with 47ohms". This sort of thing seems to be used in practical all sorts of household appliances - and tends to blow not before the warranty expired...
Improve FM reception on JVC Boombox - Page 1
Forum section: electronics / repair

author: Hogwild
author_rank: Regular Contributor
timestamp: June 25, 2024, 12:10:35 am
content: Hi all:Let's assume that I have next to no electronics knowledge other than a few basics of how to use a DMM and how to solder.I found an old JVC boombox at the curb. It works perfectly, but the FM telescopic antenna is broken. I haven't been able to source one via the web at a reasonable price. What's the best way to go about improving FM reception with that broken antenna?Thanks.

author: themadhippy
author_rank: Super Contributor
timestamp: June 25, 2024, 01:44:21 am
content: attach a bit of wire around 75cm to were the original aerial was connected

author: bdunham7
author_rank: Super Contributor
timestamp: June 25, 2024, 01:46:01 am
content: Straightening out a coat hanger is the official fix for that.

author: Hogwild
author_rank: Regular Contributor
timestamp: June 25, 2024, 03:52:55 am
content: And should I solder it to remaining stub on the antenna?

author: Teledog
author_rank: Regular Contributor
timestamp: June 25, 2024, 03:58:05 am
content: Cheap replacements here;https://www.aliexpress.com/item/1005006417661373.htmlhttps://www.aliexpress.com/item/1005006850292373.htmland more there, ..look around.Be careful, that place can become addictive!G'Luck!

author: bdunham7
author_rank: Super Contributor
timestamp: June 25, 2024, 08:57:40 pm
content: Quote from: Hogwild on June 25, 2024, 03:52:55 amWell, you can try.

author: Hogwild
author_rank: Regular Contributor
timestamp: June 26, 2024, 01:43:01 pm
content: That's very helpful. The way this antenna is mounted makes it very breakage-prone. Are there any equivalent antennas that are a little stronger/more flexible that might work well? I don't mind spending more, I just don't want to spend $USD 38.00 US, for one of the OEM replacement.

author: MathWizard
author_rank: Super Contributor
timestamp: June 30, 2024, 05:02:06 pm
content: Quote from: Hogwild on June 25, 2024, 03:52:55 amUse a flex-able wire in-between, just the weight of a coat hanger would sooner or later tear the pad and or solder off the PCB.If using the coat hanger, and you don;t plan to move it all around, I'd try and secure it nice and solid to the stereo 1st. Maybe run it down as deep inside the case as it can go, hopefully to the bottom, or tape on on the outside, nice and solid, then run your little wire out to it and solder on where ever. But what ever the order, I'd want it nice and solid.If you plan to move the ANT. around, just use extra wire, and try to have the wire near the solder joints, not move at all.

author: Hogwild
author_rank: Regular Contributor
timestamp: August 18, 2025, 05:43:39 pm
content: This repair was well worth it. The radio sounds amazing. I wish they still made them like this today.Thanks again.

author: Dougmc
author_rank: Contributor
timestamp: August 20, 2025, 01:40:00 am
content: Russell made replacement antennas.see if Ant distributorsUp there carry the line
Improving: Sumsour Rework & Sold.Station Sumsour 8586 with PCB Kasadi 8586DP 2.0 - Page 1
Forum section: electronics / repair

author: MarkFalk
author_rank: Contributor
timestamp: November 22, 2024, 03:00:30 am
content: Hi,a friend has bought a new Rework- and Soldering-Station labeled "Sumsour 8586":https://de.aliexpress.com/item/1005007973991855.html?I assume all the other same looking devices are identical.Inside is no (large) transformator but a "new" pcb by Kasadi, labeled "8586DP Ver.20 2023/03/29". Please see the pics I have made and attached.On the pcb are working two 20pin-devices labeled with "FMD" (manufacturer?) and "T4LRHDH" - no idea what kind of uC or what else this is.Some pins are connected to the both empty pin-rows labeled "RISP" (I assume: Rework ISP) and "SISP" (I assume Solder ISP) with the labels 5V, GND, SDA, SCK and RST (at RISP). So the uC (?) seems to be (re)programmable.The soldering iron does not has a temperature-sensor, it is connected with 3 wires only, 2 wires for power (half-wave: negative sinus-waves, around 300V) 1 wire for earth (connected to the tip, indeed, see pics).But it seems to has some kind of regulation, though: Due to the adjusted temperature the station sends every second a packet of negative-half-sinus-waves, the number of waves/lenght/duration of the packet is variable. It depends also on the "temperature-load" on the tip - with heavy "load" the number of half-waves/lenght/duration of the packets increases, with low load (e.g. when heating the tip otherwise) it decreases. But it does not has a sleep/standby-function (automatic decrease of themperature when putting aside) :-(.My questions:Did already anybody a reverse engineering of the circuit of the soldering-electronic?I would like to add a sleeping/standby-function. Does anybody has an idea how this can be done?
In circuit testing of smd capacitors on Mac Pro logic board - Page 1
Forum section: electronics / repair

author: jimmyc_
author_rank: Contributor
timestamp: September 13, 2021, 11:35:32 am
content: Hello chaps!I’m looking for advice on incircuit testing of smd capacitors specifically on a Mac Pro logic board.I’ve confirmed the fault is due to the Logic board. I’m not sure where the fault is, thought to start with testing the smd capacitors.Advice?

author: sean0118
author_rank: Frequent Contributor
timestamp: September 14, 2021, 02:01:02 am
content: You can test if they are short circuit, but you probably won't get accurate ESR or capacitance readings while in circuit. Check the voltages / resistance to GND of all the power rails.Check out Louis Rossmann's youtube if you haven't already.

author: jimmyc_
author_rank: Contributor
timestamp: September 15, 2021, 09:38:26 am
content: Thanks!

author: reyntjensm
author_rank: Regular Contributor
timestamp: September 15, 2021, 11:13:44 pm
content: The logic board i way too complicated to start measuring every capacitor and have a chance to find a bad cap and solve the issue like that. What model do you have? What board type? How did the issue started? Check youtube/google with the board type number. I've fixed many macbook's by looking at the most common problems on those specific devices. If it's not water damage, you should be able to find your issue online.

author: perieanuo
author_rank: Frequent Contributor
timestamp: September 16, 2021, 10:59:57 am
content: the logical thing to do is track the voltage rails or like someone suggested, track usual problems on your pcbi prefer always first one, is the thing to doif you could get some schematic or some power rails voltages, start here then after identifying the voltage rail with problems, then atttack your regulators/capacitors or whateverit's about learning also the right approach, not searching needles in haystacks. i repaired laptops intensively for almost 2 years at pcb level, never used a esr tester directly onboard, usually you got shorted caps, not degraded esr causing regulator to fail. usually == almost every time...esr tester is good for smps repair (not in circuit) and for sorting your drawers or in r&d

author: kripton2035
author_rank: Super Contributor
timestamp: September 16, 2021, 12:05:44 pm
content: this is fine to find shorted capacitorshttp://kripton2035.free.fr/Projects/shorty-display.htmlhttps://youtu.be/L4V3BWReZLY

author: David Hess
author_rank: Super Contributor
timestamp: September 16, 2021, 07:14:46 pm
content: This is not what I would recommend but it is what I would do.Assuming that the power supply is shutting down because of a shorted capacitor, I would use my own current limited low voltage power supply in its place to force a current through that supply rail, and then I would use a sensitive voltmeter to track the current, and/or search for a hot capacitor using temperature measurement.
In line bathroom extractor resistor overheating - Page 1
Forum section: electronics / repair

author: HobGoblyn
author_rank: Unknown
timestamp: December 14, 2022, 11:10:28 am
content: HiBathroom fan started oscillating on startup, for a few days it came on, went off, came on etc for a couple of mins before finally staying on properly.Then it simply oscillated.Took it out, need to replace CBB61 capacitor.But I also noticed scorch marks either end of a resistor.Resistor looks like it’s red, red, pink, gold under my microscope, presuming the pink is violet, (definitely not orange under microscope) then it should be 220 Mohm. But it measures at 22.72Kohm, which would mean the third colour is orange not violet, with the naked eye I suppose it’s orangeishThe scorch marks look to me like the resistor is getting too hot.Any suggestions please (pics attached)Thanks

author: Gyro
author_rank: Super Contributor
timestamp: December 14, 2022, 01:16:32 pm
content: Bathroom fan run-on timers like that use that resistor as a mains dropper in combination with a zener diode, to provide the [Edit: 12-15V] controller supply (basically a 4000 series logic chip and a small Triac). The resistor does dissipate a fair amount of heat in the process, but the PCB is an ordinary phenolic which browns very easily when exposed to long term (presumably years if the electrolytic capacitor failed) moderate temperatures. Yes, 22k sounds right - around 10mA supply current, so the resistor is dissipating 2.4W.You could maybe try a higher wattage resistor, or stand the resistor further off the board, but the housing is cramped and you don't want the resistor getting too close to the plastic case molding instead. It's working as designed anyway, the PCB really doesn't look that bad.
In need of a datasheet - Page 1
Forum section: electronics / repair

author: Nightowl
author_rank: Newbie
timestamp: February 07, 2020, 11:52:55 pm
content: I have searched and come up empty for a datasheet on a CM0109B TSSOP i.c. 8 legs on each side.Do you guys have a favorite site for hard to find sheets? Every place I looked said they had it, but the list doesn't show 0109b, just up to 0108.Thank you

author: fzabkar
author_rank: Super Contributor
timestamp: February 08, 2020, 12:15:00 am
content: It's a CD40109B:http://www.ti.com/lit/ds/symlink/cd40109b.pdf

author: Nightowl
author_rank: Newbie
timestamp: February 08, 2020, 03:14:32 am
content: Quote from: fzabkar on February 08, 2020, 12:15:00 amThank you. According to the pdf I have the pw0016a. All I could go by was the actual marking on the 3 I removed. I guess I need a whole lot more training to figure out new part numbers? The best part is the pad that lifted off the pcb goes nowhere! I may be able to save this thing yet.

author: fzabkar
author_rank: Super Contributor
timestamp: February 08, 2020, 06:46:00 am
content: Here are just a few searches I use:http://www.smdmark.com/en-US/search/code?id=CM0109Bhttps://www.google.com/search?q=filetype:pdf+cm0109bhttp://www.ti.com/packaging/docs/partlookup.tsp?searchType=partmark&keyword=&partNumber=&partmarking=cm0109b
Incorrect Tektronic 7623A voltage - Page 1
Forum section: electronics / repair

author: Rento
author_rank: Newbie
timestamp: April 26, 2023, 10:02:15 am
content: Hello everyone, I introduce myself: I'm Rento, electrical engineer passionate about electronics, I'm Italian and I don't know English well. I immediately apologize if with the google translator I could not explain or understand you well, I could ask you twice for the things I didn't understand, have mercy and patience. First time in a forum I hope I'm not too wrong.Help I have a problem with the repair of a Tektronix 7623A, they gave it to me, it worked fine even if it had problems on the horizontal, then one day a strange shape appeared at 45° as Sean0118 said in his discussion.The facts: it had all the voltages ok except -15V (-11.2), I made some measurements and checks but nothing strange. I was following the discussion of Sean0118 and co, very useful, but at one point the tragedy! I took out P901 to section a board but now all voltages are busted.Voltages before were PP901 (starting in pin order) -53 -19 0 +18 +53 130 40 now I'm -72.9 -17.5 13.1 25.3 96.9 -15.9On the board connector horizontal and vertical voltages from +50 +15 +5 gnd -15 -50 now I'm +26.9 23.4 +5 gnd -11.2 -50. Also detaching P980 to vote I read 130 -> 98.5 +40 -> -14.6 +53 I don't remember, but no-53 -> -73.8. First question what triggered all this, just by unplugging a connector? After the first heart attack now I found Q926 shorted. Now I ask you for help, what do you suggest to do, how to proceed? I would like to check A11 rectifierd board, but it scares me a bit to disassemble everything, I don't have a clear idea of ​​how to do it. Suggestions are accepted. Sorru if as a first post I made some mistakes, I will learn. thank you very much.
Indesit induction hob VID 641 BC "F47" error - Page 1
Forum section: electronics / repair

author: grumpydoc
author_rank: Super Contributor
timestamp: January 17, 2023, 09:06:20 pm
content: HiAnyone know anything about these hobs, such as whether there is a service manual available, or even just a list of fault codes which is more informative than "refer to service centre".I have one - works intermittently then comes up with F47. Rarely gets through a whole meal. Turning it off and waiting usually clears the error eventually (resettable thermal fuse?).It's not at my main place, so test equipment is a bit limited. I have a multimeter and that's about it.

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 18, 2023, 10:45:53 pm
content: I can't seem to find internal photos of your model. Repaired some from Merloni group in the past, they would throw random errors during use due to electrolytics on switching PCB.See attachment for concerned model.

author: grumpydoc
author_rank: Super Contributor
timestamp: January 19, 2023, 07:04:58 pm
content: Thanks for your reply, I can't find much on it either - looking today it appears to be identical to the Tekia IR 641 (but I'm having just as much luck looking for info on that model)The one hit on the Tekia also suggested that F47 is a power supply issue.
Indium Foil Thermal Pad - Page 1
Forum section: electronics / repair

author: 2X
author_rank: Frequent Contributor
timestamp: May 18, 2024, 09:50:10 pm
content: Hello,I remove the below heatsink (at the attached image) where it had indium foil thermal pad. As I read on the internet indium foils don't have a very good thermal conductivity. Do you know if there is a specific reason for the using of indium foil? Can I use a thin thermal pad instead of indium foil?

author: David Hess
author_rank: Super Contributor
timestamp: May 19, 2024, 12:29:13 am
content: The thermal conductivity of indium is not that good, but the layer of metal once applied is very thin.

author: coppercone2
author_rank: Super Contributor
timestamp: May 19, 2024, 01:58:11 am
content: the thermal conductivity according to tests is very similar to thermal compound with the mid range pad.the reason is clean and easy to apply, just expensive (so are good silpads for processor heat density levels)I expect the difference will be within a few percent if you get the best thermal paste.this makes me think it hardly matershttps://hardforum.com/threads/arctic-mx-5-vs-indium-foil-diy-thermal-pad.2011670/

author: 2X
author_rank: Frequent Contributor
timestamp: May 19, 2024, 08:14:54 pm
content: I beleive the designer select to put aluminum foil because the heatsink was placed in a way that can't be detached easy (attached picture). If he was puting paste it has to replaced in short periode of times. Instead of the Indium foil where it has a very longer life (maybe it will not replaced ever). I don't know if I will find a so thin (0.1mm) thermal pad in reasonable price, so I will stay with the designer's choice (or if I try another solution I will tell you about the results).P.S. This way of holding the heatsing (at the attached picture - I don't know if it has a specific term/name) it seems to me cheap.. why they just put two screws?

author: coppercone2
author_rank: Super Contributor
timestamp: May 19, 2024, 08:20:24 pm
content: its indium not aluminum and that spring will never loosen
Induction cooktop beeping noise - Page 1
Forum section: electronics / repair

author: Robertas
author_rank: Newbie
timestamp: August 03, 2020, 01:07:14 am
content: So i used a brand new iduction coock top and after i used it it started beeping like crazy from the power plug and i have no idea what is wrong whit it. i tryed unpluging it but i didnt help. i beg you from help it has been going for almost 3h now and i think im going crazyi have a video of it here:https://www.youtube.com/watch?v=i7d-xe9CLG0&feature=youtu.be

author: tooki
author_rank: Super Contributor
timestamp: August 03, 2020, 09:22:42 am
content: I’d call that a metallic “chirping” more than beeping, since “beeping” is generally reserved for tones created on purpose, but this is definitely not intentional.Anyway, you’ve left out some other key info: does the cooktop actually work? What are the test conditions here: Does this sound occur only when turned on? Or turned off? (I can’t quite make out if the cooktop is powered on or not.)It’s definitely not coming from the plug itself. It’ll be sound coming out into the cabinet where the socket is, but not coming from the plug. It sounds to me like a power supply trying to start up, but it’s also a very similar sound to an induction stove actually heating a pan. You get a similar interrupted metallic chirping when an induction stove is having trouble detecting a pan, and keeps cycling a burner on and off as it tries to turn on, doesn’t detect a pan properly, and then turns off and tries again a moment later.It looks like it’s plugged into a 230V socket. Is the cooktop configured for 230V single-phase, or is it configured for 400V three-phase? (Some can be configured for either.)
Industrial LCD display - Page 1
Forum section: electronics / repair

author: Gominalo
author_rank: Contributor
timestamp: November 07, 2024, 04:21:20 pm
content: Hi all,I am facing to a LCD display that died suddently during weekend. I've been checking voltages and they seem to be okay, next step i think will be T-CON pcb.Can anyone guide me through troubleshooting? (Signals to be checked, power-up sequence...)The display is used for a semiconductor wafer prober, see photos.Thank you.

author: BennoG
author_rank: Frequent Contributor
timestamp: November 07, 2024, 05:48:21 pm
content: usually the backlight breaks down on this type of units.If you shine a bright light on the front can you see the image a little ?Benno

author: coromonadalix
author_rank: Super Contributor
timestamp: November 07, 2024, 05:53:50 pm
content: the backlight board as 4 outputs on it, or 2 in parallel ?check if you see markings on it, who would help you for voltages and control pinst-con is not for backlight ...do i see tdk something on the ccfl board can you show us photos or write the numbers

author: Gominalo
author_rank: Contributor
timestamp: November 07, 2024, 06:24:58 pm
content: Quote from: BennoG on November 07, 2024, 05:48:21 pmThat has been checked by another person and told me that there's no image but i'll check by myself.Thank you.

author: Gominalo
author_rank: Contributor
timestamp: November 07, 2024, 06:27:36 pm
content: Quote from: coromonadalix on November 07, 2024, 05:53:50 pmI supose that like others ccfl there are two tubes in series per side of the LCD that's why i have 4 connectors.TDK S/N is: PCU-P235BThank you.

author: dietert1
author_rank: Super Contributor
timestamp: November 07, 2024, 07:06:07 pm
content: Roughly a year ago i converted two old Samsung computer displays from CCFL to LED, using a kit (probably Chinese origin). After one of the displays got ready and was working well i ordered another kit and did the second one. One has to take apart the display anyway in order to fix the backlight, and the LED solution is much better: less energy consumption and less heat. Hope it will last some more years.Regards, Dieter

author: Gominalo
author_rank: Contributor
timestamp: November 08, 2024, 09:26:50 am
content: I've identified a bad smd component, i think it is a diode.Before it there's only one thing, the connector wich supplies 12v directly to it, the diode is not conducting anymore. Can anyone help me identifying?It is located in the high voltage pcb for the ccfl backlight.Thanks.

author: inse
author_rank: Super Contributor
timestamp: November 08, 2024, 10:55:42 am
content: “50“ is possibly a fuse, measure resistance across the capacitor below, it might give a hint why it blew (if it’s a fuse)

author: coromonadalix
author_rank: Super Contributor
timestamp: November 08, 2024, 09:18:00 pm
content: 50 would be an inductance way thicker than the 202 resistor near itgive us the chip marking near them, search datasheet could give you something to work with
Infant Optics DXR-8 Baby Monitor Repair - Page 1
Forum section: electronics / repair

author: elimenohpee
author_rank: Contributor
timestamp: November 25, 2023, 04:05:50 pm
content: I have a baby monitor that randomly quit working. Leading up to the failure, I noticed the LiPO battery wouldn't charge so I took it apart thinking maybe it was the charging IC. It seems as if the processor has died but wanted to check if anyone had any other suggestions. Here's what I've done so far:-SAT 3.3V and 5V power rails-SAT clock signal into the main processor-NO data on the TX/RX UART port-NO data on any of the LCD signals coming off the processor-NO SPI data/clock between processor and RF IC-NO clock signal on the 18Mhz crystal for the RF receiver chip... not sure if this could be a culprit somehowUK1 - Sonix SN9300U6 - AMIC A7121UP3 - THX202H Buck switching converterUF1 - FP8102 LiPO charging ICAny other thoughts to check? Not sure how the processor would have failed but that is the only thing I can think of
Infiinium 54810 - Page 1
Forum section: electronics / repair

author: rtekal
author_rank: Contributor
timestamp: June 26, 2020, 10:45:45 am
content: Hi,I have a Infiinium 54810 A oscilloscope. The peculiar problem I am facing is that on Channel 2 the input resistance selection is inverted. The 1Mohm setting is giving a 50 Ohm impedance and vice versa. This prevents me from doing a Calibration. The self test shows no errors.I have tried swapping / replacing the Channel 2 input attenuator and the Acquisition board also. But the issue remains the same. Is it due to the expiry of the life of the attenuator or is there a software code that kills after a predetermined usage . Messages are displayed after self test that the switches are beyond their life expectancy and have to be replaced.Regards

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: June 27, 2020, 03:09:21 pm
content: Are you referring to the "Attenuator Contact Warning" This only means that the attenuator contact has exceeded 2 million click,. It does not mean it has failed. There does not appear that the unit takes any action on this message, since recommendation for bench use after warning is just to watch the unit.This is from the Infiniium 54810 Service Guide. It is a warning to folks who use this unit in production monitoring to warn them about possible future failure. It is kind of a "mileage counter".Are you noticing the 50 Ohm / 1 Meg switch while using a probe or just connecting to BNC to AUX OUT???Wally

author: rtekal
author_rank: Contributor
timestamp: June 30, 2020, 05:31:18 am
content: It was the same when connecting the probe also.Well it resolved after I removed and reconnected the board and the attenuators. It passed calibration. But still wonder why that behaviour.Thanks for the response

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: July 02, 2020, 12:47:58 am
content: I had a similar problem using old Tek probes. The probes had broken wires in the 10X sensor pin. Made the 54810 go nuts. It didn't know what the input was. Kept switching at apparently random times to 50 ohm I suppose the broken wire was contacting intermittently and confusing the input sensor.Probably you had a similar problem but with an intermittent connection in the 10 X sensor path and fixed it by fixing/cleaning the bad connection in the 10X sensor pin path.I took apart the old Tek probes and fixed the broken wire problem and they now work, but I do not think I will use them much.By the way, you can upgrade the 54810 to 2Gs from 1Gs. There is a thread on this somewhere here. Very easy to do.Also there is a way to change the hard drive to solid state drive.The 54810 is my first modern digital scope. I really like it, I had older digital scopes that I did not care for at all.Wally
Infiinium DSO 9104 power on failure. - Page 1
Forum section: electronics / repair

author: rtekal
author_rank: Contributor
timestamp: October 28, 2020, 08:21:15 am
content: Hi,I have a Agilent Infiinium DSO 9104 which fails to power up. Upon pressing the power button, The sequence 2 error led's glow pointing to a failure of the +1.2 volt , shutting down the supply. This voltage is monitored by U497 LTC2928. There are three cascaded monitoring circuits monitoring all the voltages on the acquisition board. All the on board supplies are sequentially switched on, monitored and then only the instrument boots up. The main +12 volt bulk supply is good.The LED's in Seq 2 glows as follows.LED's 1 & 2 : ONLED's 3 & 4 : OFF.Has anyone repaired the power supply failure on the acquisition board?Regards

author: F1GWR
author_rank: Regular Contributor
timestamp: August 14, 2024, 09:05:38 am
content: Hi,Almost same issue here with my DSO9404A. Instead I'm in sequence 3 with - 8.3 V "command" failure (sequ 3 LED 3 on).Did you experience any success on your side?

author: rtekal
author_rank: Contributor
timestamp: September 04, 2024, 04:09:24 am
content: No. Got the Acquisition board replacedRegards
Infinity Overture 2 amp signal path question - Page 1
Forum section: electronics / repair

author: byoungblood
author_rank: Contributor
timestamp: December 21, 2022, 12:09:33 am
content: I am trying to troubleshoot this amplifier in this powered speaker. I understand the signal path to the 2N3906 Q6, but I am a bit lost between there and the bases of Q10 and Q12.Is R63 a feedback path from the output?Also, the bias is supposed to be adjusted via POT2. I can turn it fully in each direction but there is no change to the bias of any of the 4 output MOSFETS. There is supposed to be about 5.9mV dropped across R77 on the source lead of Q13, but I only measure 5.0mV (not off by much) but the potentiometer has no impact on the bias of the MOSFETS at all.Thanks in advance.

author: velixzeen
author_rank: Newbie
timestamp: March 30, 2023, 11:09:09 am
content: Hello byb, just read your post about the O2 amp. Any luck figuring out the cct and o/p path? I have a pair of O3 speakers and they use the same amp judging from the schematic you posted. I'm looking for information and noted you had a spec of 5.9mV drop on R77. Where did you get that value? Can you post a link or something?Like you I wondered about the path IN to OUT on this. I hope the schematic is accurate. Perhaps one could throw this into multisim and simulate it?Does turning the POT2 move the bias of Q11, the 2SD2012?
Info on a Vintage Delmhorst RC-1B Moisture Meter - Page 1
Forum section: electronics / repair

author: VeeDubBub
author_rank: Newbie
timestamp: November 14, 2021, 05:08:44 am
content: I have acquired a vintage Delmhorst RC-1B wood moisture meter and I cannot find any info on it, I can find info on newer models that use a 9V battery, but this meter uses a 1U4 amplifier tube. It uses 4 X 22.5 volt alkaline batteries in series for a probe voltage of 86 volts!If anyone knows of a source for a schematic that would be great. It has a very simple point to point electrical layout, just curious if there is a schematic out there.I will reverse engineer a schematic for it while cleaning it up and replacing any resistors that are out of spec.
Info Required on H-7XNMD0007 10MHz :: SOLVED - Page 1
Forum section: electronics / repair

author: Labrat101
author_rank: Unknown
timestamp: February 25, 2021, 01:05:31 pm
content: Hi, AllI would like to know if any one has ever seen one of these Oscillator 10Mhz boards before and has any information on it .I have acquired one and there seem to be no information available . There are plenty showing on Ebay etc . I guess someonetook them from a Cell tower or similar .Thanks in advance .Yes, I could just put power on it and a scope . and see what happens .There is a 4 terminal power connector . The caps are rated at 16v so its properly 5v OXCO Maybe 12V .So if anyone has fired up one of these boards I would like to know .Thanks

author: Labrat101
author_rank: Unknown
timestamp: March 03, 2021, 07:06:35 pm
content: SOLVEDHi ,OK Thanks I guess No one else has one of these NDK 10Mhz Osc boards.They are are made by JRC ( Japanese Radio Corp. )It was horribly out of Cal. When I Acquired it .After a little reverse eng. and some a few probe tests I managed to fire it up .So the outputs worked .It has A Cal screw on the back side .I used a dual port Neo Bodnar GPSDO and used that as my reference for the HP5385A.The 4 pins are :-O O O O ( right )+ P nc -P = Pulse, Pos Pulse ON & Neg Pulse OFF .OCXO is 5 VoltIt supply voltage to Connector 7 to 12 volt Current 22ma Max loadIt requires a thermal over coat as it is very sensitive to drafts etc.
Infocus IN5110 Projector Ballast Issue - Lamp lights up once out of 15 - Page 1
Forum section: electronics / repair

author: thitou
author_rank: Contributor
timestamp: January 18, 2024, 04:55:05 pm
content: Hello, I'm currently experiencing a problem with my Infocus IN5110 projector.Everything works correctly except the lamp lighting. I sometimes have to turn the projector on and off several times (15-20x) to get a lamp strike. I do hear a very short arcing noise each time. I think it's just too weak/short to ignite the lamp.However, once the lamp decide strikes, the projector lights up correctly and never goes out. So I guess my problem lies in the part of the ballast that manages the initial arc. What do you think?I checked the communication between the ballast and the motherboard, and the 380v power supply to the ballast. Everything works fine on this side.I tried another lamp from a working projector, same problem... This one doesn't strike either.The ballast is definitely defective.I tried to repair it, checked the transistors, the diodes, no short circuit to report.As I'm more or less new to power supply repair, I'd like your help with the schematic of this power supply. Here's a image of the schematic (Blue arrow = DC IN 380V -- Yellow arrow = Lamp Out), where is the part responsible for the starting arc? I think it's called the igniter. Do you have any other ideas about the source of the problem?Perhaps the high-voltage capacitors?Thank you very much for your answers! Any suggestions would be greatly appreciated!
Inline dangling capacitor fell off Onkyo A-RV401 Receiver - Page 1
Forum section: electronics / repair

author: smk279
author_rank: Contributor
timestamp: December 15, 2023, 06:13:40 pm
content: Where do the wires go?https://imgur.com/a/8v9pRzP

author: Jwillis
author_rank: Super Contributor
timestamp: December 15, 2023, 08:01:55 pm
content: Looks like something someone podged in. Not factory. Could go anywhere depending on what it was supposed to do.

author: smk279
author_rank: Contributor
timestamp: December 15, 2023, 11:35:30 pm
content: I replaced a lot of burned out resistors of all types and even one of the big transistors that attaches to the heat sink but I didn't see any caps that looked faulty Why would someone have done that Maybe Onkyo did it as a hack to fix a problem with the original design?

author: darkspr1te
author_rank: Frequent Contributor
timestamp: December 16, 2023, 05:20:34 am
content: I see this often in a lot A/V units, most of the time it because the repair tech cannot get the same physical size cap for the location on the board or the original part was too under spec and the board space does not allow for a larger part (lot of old jap pioneers are like this)i would look around the boards for a missing cap , it is most likely for there. take your time and look close at the solder side of the pcb as you might see the two points it was attached. The voltage of the cap also will define where its located , so lower 16v caps would be in audio filters but higher 50v spec would be in output stage or power supply.it's one of those job that you are going to have to look close at the pcb, pictures might help us but you have the board and can tilt, move and illuminate to best see the solder points.darkspr1te

author: smk279
author_rank: Contributor
timestamp: December 16, 2023, 05:45:36 am
content: It's 16V 6800uF
Inmel / Lumel SQ10 Calibrator: Searching schematic or service manual  - Page 1
Forum section: electronics / repair

author: richipedia
author_rank: Contributor
timestamp: February 06, 2021, 09:37:40 pm
content: Hello everybody,I've got this beautiful Inmel SQ10 calibrator lying around.Unfortunately, the 100 V and 1000 V ranges are not working, and the other ranges seem to be a little out of calibration.Can anybody provide me with a service manual, or in particular a schematic or a calibration procedure?

author: Robert999
author_rank: Newbie
timestamp: January 16, 2024, 01:02:40 pm
content: Dzień dobry , mam pytanie czy udało się Panu naprawić kalibrator sq10 ?Pozdrawiam
Inner Range Elite LCD Terminal Schematic/Repair manual? - Page 1
Forum section: electronics / repair

author: Tony_G
author_rank: Super Contributor
timestamp: April 17, 2022, 05:45:09 pm
content: Hey All,I have a Concept 3000 security system from Inner Range setup here at home and the LCD terminal has crapped itself - I've verified that there is power and data getting to the terminal location and looking at the board shows an SMT component that seems to have blown.Obligatory badly taken picture:Blown componentDoes anyone happen to have a schematic or repair/service manual for the Elite LCD Terminal? Would like to know what M1 is supposed to be to see if it is something that can be fixed.Thanks,TonyG
Inop fluke 189. - Page 1
Forum section: electronics / repair

author: Tech_Monkey
author_rank: Contributor
timestamp: November 03, 2022, 02:48:17 am
content: A friend gave me this today after hearing me talk about some power issues. Said it didn't work but that i might be able too fix it and if so i could have it. I saw some manuals and instructions on troubleshooting elsewhere on the forum... ill start that tomorrow.. first things first i just wanted to post some pictures out here to see if someone more knowledgeable can immediately find something not worth my time. I only see one burned/damaged component which i have posted pictures of.

author: Tech_Monkey
author_rank: Contributor
timestamp: November 03, 2022, 02:48:59 am
content: One more

author: BILLPOD
author_rank: Frequent Contributor
timestamp: November 03, 2022, 06:14:26 pm
content: Can you post some closeups of the suspected area?;as these wide angle photos don't give enough detail

author: Tech_Monkey
author_rank: Contributor
timestamp: November 08, 2022, 06:13:46 pm
content: Sorry I havent had time to do anything on the forum. The transformer (or inductor?) whatever it is that looks brown was not an issue. I pulled the supercap out and cleaned the battery terminals and it started right up.
input jacks on DC load? - Page 1
Forum section: electronics / repair

author: analogRF
author_rank: Super Contributor
timestamp: August 27, 2019, 02:28:58 pm
content: I have managed to break one of the connectors on my BK Precision 8500 DC load.It is still usable but I would like to replace it.I cannot seem to find the proper replacement. Can anybody point me to the right part perhaps on digikey or anywhere else?thanks

author: PKTKS
author_rank: Super Contributor
timestamp: August 27, 2019, 03:20:13 pm
content: Acceptable quality for the price...more than 30A I never use BANANAS binding posts.instead I go ANDERSON power poleshttps://www.aliexpress.com/item/32748606671.htmlPaul

author: analogRF
author_rank: Super Contributor
timestamp: August 27, 2019, 03:25:02 pm
content: Quote from: PKTKS on August 27, 2019, 03:20:13 pmyeah, I found many of these but (1) they are all banana and I don't want banana plug. the original connectors on BK 8500 are two bulky bolts and no banana plug (see Dave teardown video or IT8512 teardown on eevblog) (2) their size dont seem to fit BK 8500. They seem too short and a bit too thin.

author: schmitt trigger
author_rank: Super Contributor
timestamp: August 27, 2019, 03:43:58 pm
content: You might try to contact B&K to see if they will sell you service parts.It helps a lot if you have an user's manual with an exploded mechanical view and/or BOM which lists B&K's part numbers.

author: PKTKS
author_rank: Super Contributor
timestamp: August 27, 2019, 03:49:09 pm
content: Just in case they don't sell such parts per si...there are a plethora of videos on youtube from HAM folksadapting ANDERSON in several ways and power ranges.A hack inside your panel is usually good enough..but the minor finishing is always tricky.Once installed on the panels ANDERSON is the thing:"INSTALL AND FORGET..." almost any power rangePaul
Instant laptop capacity loss? - Page 1
Forum section: electronics / repair

author: e-pirate
author_rank: Regular Contributor
timestamp: November 26, 2020, 10:03:05 pm
content: Hi folks.Just got a fresh battery for my oldish Lenovo X230. The battery is less then a week old and gone through 3-5 discharge cycles.Today I noticed that it already lost 5% of it's original capacity:# acpitool -BRemaining capacity : 53550 mWh, 98.49%Design capacity : 57720 mWhLast full capacity : 54370 mWh, 94.20% of design capacityCapacity loss : 5.804%Present rate : 0 mWCharging state : UnknownBattery type : Li-ionModel number : 45N1025Serial number : 19141I checked the battery yesterday and it showed 0.1% capacity loss. Besides, today the laptop failed to go to the sleep mode (this happen time to time to my X230) and the machine was hanging ON with fan running in my backpack unattended for about 40 minutes. But it was idling and when I found this, the case was just warm, maybe 40-45 C - this should not be a problem for LiIon that is 85% charged AFAIK.Could this be related?Can I do something about this?How this numbers acre actually calculated without going through full cycle?

author: Haenk
author_rank: Super Contributor
timestamp: November 27, 2020, 10:04:11 am
content: Original or 3rd party battery?I think the "latest" BIOS plus battery tool (AFAIR this is even pushed to the machine via Windows Update) don't like 3rd party batteries.

author: e-pirate
author_rank: Regular Contributor
timestamp: November 27, 2020, 11:44:03 am
content: Quote from: Haenk on November 27, 2020, 10:04:11 amWell.. it's very difficult to say if it is truly original or not. It is claimed Lenovo, it is recognized by the original non-patched BIOS and look like original (except the logo which is slightly different font, but that may be legit as Lenovo office light box here in Moscow has same different font this days). And the machine never booted with widnows since it was bought in late 2013, so no sh*ty updates. The battery cost me 2550 Rubles (about 32 Euro) and that is at least 2 times 3rd party price. Frankly speaking, I have no clue if it is original or not. All except the font including SN sticker, date code, plastic, rubber foot looks like my original 7 y.o. pack.
instek GOS 6112 - Page 1
Forum section: electronics / repair

author: Shopy
author_rank: Contributor
timestamp: May 13, 2020, 11:26:33 am
content: hello expertsi like to ask for your helpI have this scope and when I connect the probe X1 to the CAL I do not get 2v p/p it is less than 2 v.how I calibrate this so it will show 2v p/p/attached is what I getthanks
Instek GOS-620 oscilloscope sweep troobleshooting - Page 1
Forum section: electronics / repair

author: Aboujjik
author_rank: Newbie
timestamp: February 21, 2023, 07:38:36 pm
content: Good day allI have a problem with my oscilloscope GOS620, i can see the Y axis trace but so sweep on x axis except when pushing power button the first time, i see a fast sweep then the dots representing the low and high voltage of the oscilloscope internal pulse generator. I can move the dots with the position knob left and right and up and down. Dots are changing its position very slowly like 1 division / 5 min.. please advise.Please check attached photosAnd the instrument pcb designRegards

author: leon255
author_rank: Newbie
timestamp: August 10, 2023, 06:43:38 pm
content: Check U408 (GAL16V8)
Instek GOS-6200, no more delayed sweep operation - Page 1
Forum section: electronics / repair

author: wodi
author_rank: Newbie
timestamp: January 15, 2021, 04:38:46 pm
content: Can someone help me to find out what's broken on my GOS-6200. All functions are available except delayed sweep operation. I can mark the specific part but no magnified graph is visible even not in trace sep mode. Unfortunately schematics available at download links are not readable good enough and at page 12 half page is missing. Many thanks for any hint what to check.
Instek GPS2303 - screen panel slowly died - Page 1
Forum section: electronics / repair

author: f0raster0
author_rank: Newbie
timestamp: February 17, 2020, 06:54:20 am
content: Hi guys,We borrow a lab supply Instek GPS2303, and we broke it :-(https://www.eevblog.com/forum/reviews/instek-gps2303/msg97795/#msg97795We were using this for some testing and got some unusual results. The screen panel slowly died and then went blank. We tested output etc afterwards, and everything else appears to be working.Inside everything looks "OK",Do you have any tips, idea to start debugging it, looks like just the screen panel is not working.thanks very much

author: Gyro
author_rank: Super Contributor
timestamp: February 17, 2020, 10:58:22 am
content: Welcome.I'm curious about the 'slowly died' bit. What were you testing on the outputs?I killed the displays on mine once, but that was by accidentally applying an excessive voltage (up to 1kV) between the two outputs and also relative to ground (Don't ask!). I'm just wondering if you did something similarly silly.There are separate supplies to the two channels from the transformer to drive the control circuits. Each display is driven by a standard ICL7107 DVM chip (4 total).

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: February 17, 2020, 06:54:31 pm
content: The front panel is powered from separate winding on the transformer... I would first check if you have AC coming to your front display assembly. After this it's very simple power supply... check fuse if there is any, check rectifier, regulator and so on. It shouldn't be lot of checking.I have one of those but I've never taken it apart.So, if I'm correct the power supply is still working you just can't see the settings for the channels?