hybridfree/eevblog-posts huggingface dataset:
What is this resistor? - Page 1
Forum section: electronics / repair

author: sr3323
author_rank: Newbie
timestamp: May 26, 2019, 01:11:36 am
content: It was out of a PS4 power supply that has no 12V output. The board says "R11" so I assume it is a resistor and not an inductor. This doesn't seem to follow regular color codes. My meter says it's 0 ohms. Thanks!

author: Ian.M
author_rank: Super Contributor
timestamp: May 26, 2019, 01:51:35 am
content: Red 2Blue 6Silver *0.01Gold 5%Black==> 0.26R 5%The fifth (black) band is unlikely to indicate a TC of 250ppm/K, as 5% resistors don't usually specify the TC. Its not a valid colour for reliability or to specify high stability or fusible, so its probably a manufacturer specific code. As its virtually impossible to determine the manufacturer, that's a dead end.It appears to be a non-flammable wirewound resistor, and without a mm scale in the picture we can't estimate its power rating.

author: wraper
author_rank: Unknown
timestamp: May 26, 2019, 01:58:23 am
content: Quote from: sr3323 on May 26, 2019, 01:11:36 amIf you know it has low resistance, why would you bother desoldering it? It's obvious it's not faulty.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 26, 2019, 02:24:36 am
content: wirewound resistor0.265 ohms 1% the third color is it green ?once out of the circuit does it still say around 0 ohms ?If your meter permis it, can you zero out the probes values ??

author: Doogs
author_rank: Contributor
timestamp: May 26, 2019, 02:29:12 am
content: Best guess is it's a 26 ohm at 0.5% and they used the black instead of green for the last band for production reasons, 0.5% seems rather specific for just a power supply resistor though. ETA: you could see if there's another one on the board and measure it;
What is this smd code IC? - Page 1
Forum section: electronics / repair

author: wawinfo
author_rank: Contributor
timestamp: February 28, 2024, 10:14:25 am
content: Can anyone please help to find this 2 ic on board?

author: fzabkar
author_rank: Super Contributor
timestamp: February 28, 2024, 05:40:23 pm
content: SI3442BDV, Vishay Siliconix, N-Channel 2.5-V (G-S) MOSFET, 20V, 3.4A, marking 2Bxxx, TSOP-6:https://www.vishay.com/docs/72504/si3442bd.pdfhttps://aliexpress.com/item/33021849794.html(photo)http://markingcodes.com/search/c/2Bxxx
What is this thing? Need Help. - Page 1
Forum section: electronics / repair

author: Ussovak
author_rank: Contributor
timestamp: May 01, 2021, 12:51:14 pm
content: Does anyone know what this is? I know it's made by Advanced Analogics Circuits but I cannot find anything about it. Perhaps I'm missing a crucial letter due to the explosion and the crater left behind.Can someone help?

author: gamalot
author_rank: Super Contributor
timestamp: May 01, 2021, 01:05:17 pm
content: AZ1117CH-5.0TRG1https://www.diodes.com/assets/Datasheets/AZ1117C.pdf

author: Ussovak
author_rank: Contributor
timestamp: May 01, 2021, 01:27:04 pm
content: Thanks. How did you cross-ref this?

author: gamalot
author_rank: Super Contributor
timestamp: May 01, 2021, 01:56:25 pm
content: Quote from: Ussovak on May 01, 2021, 01:27:04 pmSorry, maybe I made a mistake! I found another chip with the same marking pattern. Now I am not sure which one is right, and I am not sure if there are more similar chips!AP2114H-3.3TRG1https://www.diodes.com/assets/Datasheets/AP2114.pdfMaybe you can use the working voltage of other chips on the PCB to determine whether it is 5 or 3.3V.

author: Ussovak
author_rank: Contributor
timestamp: May 01, 2021, 01:59:22 pm
content: Still very helpful. Thank you.

author: gamalot
author_rank: Super Contributor
timestamp: May 01, 2021, 01:59:32 pm
content: Most of the time, I identify them by searching the package and marking of the chip on Taobao.

author: Ussovak
author_rank: Contributor
timestamp: May 01, 2021, 02:06:57 pm
content: That's great. Thanks again. I will attempt to ID which one by measuring the voltages around the circuit.

author: fzabkar
author_rank: Super Contributor
timestamp: May 01, 2021, 07:26:41 pm
content: I don't feel comfortable about this one ...GH4 = AP2210N-3.0TRG1https://www.diodes.com/assets/Datasheets/AP2210.pdfhttp://www.smdmark.com/en-US/search/code?id=gh4http://www.smdmark.com/en-US/search/code?id=gh1

author: gamalot
author_rank: Super Contributor
timestamp: May 02, 2021, 07:15:43 pm
content: Quote from: fzabkar on May 01, 2021, 07:26:41 pmAP2210 is only available in SOT23 package

author: JayArr
author_rank: Contributor
timestamp: May 04, 2021, 06:08:54 am
content: I use a cross reference from Turuta. I've been using it for ten years now and it solves most mysteries. It's not free, I think I pay $20 and I don't buy it every year, just every few years.www.turuta.md
what is this transistor please - Page 1
Forum section: electronics / repair

author: electrolust
author_rank: Unknown
timestamp: September 03, 2023, 11:08:41 pm
content: only finding 2n5671 in TO-220 or bottlecap package. this looks to be TO-92.this is from an automotive electtronic diff controller, +12v input to the board.

author: wraper
author_rank: Unknown
timestamp: September 03, 2023, 11:12:41 pm
content: This looks like Japanese stuff from 80's or 90's

author: wasedadoc
author_rank: Super Contributor
timestamp: September 03, 2023, 11:38:49 pm
content: If Japanese it could be 2SC5671. I did find that number in a list of Panasonic discontinued items.http://www.rf-china.com/pdffile/panasonic.pdfpage 130. Have not been able to find specs.

author: Kim Christensen
author_rank: Super Contributor
timestamp: September 03, 2023, 11:55:51 pm
content: It's a bit blurry... But I see a S & G on the silkscreen. So it's probably a mosfet of some sort.

author: rsjsouza
author_rank: Super Contributor
timestamp: September 04, 2023, 10:14:48 am
content: Quote from: electrolust on September 03, 2023, 11:08:41 pmThis is a TO-226 package used in higher power transistors.https://eesemi.com/to226.htmThe code 2SC5671 returns a lot of brokers but no significant specifications data, unfortunately. The markings on the PCB indeed hint to a FET, but it could be a JFET instead of a MOSFET. This packaging is not as popular today as it was in the era where JFETs were all the rage.Good luck finding additional info.

author: BrokenYugo
author_rank: Super Contributor
timestamp: September 04, 2023, 01:00:55 pm
content: Since there appears to be more than one on the board perhaps a good one could be removed for testing? Confirm MOSFET, N or P channel, enhancement/depletion, get the gate threshold voltage, and get an idea of what it does in circuit, something close enough (or sufficiently overkill) can probably be selected from there.If 2SC5671 is the number all I could find in hard data is it listed in a discontinued devices section of an old Panasonic transistor catalog.EDIT:Wait, if FET then wouldn't it be 2SK (N type) or 2SJ (P type), not 2SC?2SJ567 is a P channel enhancement MOSFET, closest I could come up with.https://toshiba.semicon-storage.com/info/2SJ567_datasheet_en_20100205.pdf?did=12987&prodName=2SJ567

author: electrolust
author_rank: Unknown
timestamp: September 04, 2023, 09:27:23 pm
content: This is japanese, 80s/90s. I found this available in SOT-323 package, $3.00. I guess I could just wire it in on the back side if I can't find it in the same package. I'll remove a good one and see what I can learn about it.

author: electrolust
author_rank: Unknown
timestamp: September 04, 2023, 09:32:42 pm
content: BTW it got fried from reverse polarity

author: fzabkar
author_rank: Super Contributor
timestamp: September 04, 2023, 09:39:28 pm
content: Automotive parts often have customer part numbers rather than IC manufacturer's numbers. What I find suspicious is that there is no J or K to tell us whether the part is N-channel or P-channel. This leads me to suspect that the part number is the customer's own.
What is this type of spring called? - Page 1
Forum section: electronics / repair

author: rea5245
author_rank: Frequent Contributor
timestamp: August 08, 2021, 05:53:27 pm
content: I'm working on restoring a Heathkit H9 terminal. There's something the instructions refer to as a "tension spring" that looks like a springy piece of metal, that slips into a groove and holds the bezel in place.Googling for "tension spring" gives me a very different type of product. What is the right name for this?Thank you.

author: BrokenYugo
author_rank: Super Contributor
timestamp: August 08, 2021, 06:05:39 pm
content: It's a sort of flat spring, you'll probably have to make them if you need any.

author: jpanhalt
author_rank: Super Contributor
timestamp: August 08, 2021, 06:22:19 pm
content: Might be called a wave spring:https://www.mcmaster.com/springs/linear-wave-springs/You can cut from that or from a disk spring:https://www.mcmaster.com/springs/corrosion-resistant-curved-disc-springs/

author: Gyro
author_rank: Super Contributor
timestamp: August 08, 2021, 07:05:53 pm
content: It's a small example of a 'leaf spring' isn't it?P.S. You might be able to cut sections from an old clock spring.

author: Tony_G
author_rank: Super Contributor
timestamp: August 09, 2021, 12:17:53 am
content: Not sure if this helps but over on the HPAK group people often suggest using a piece cut from a feeler gauge as a replacement spring in buttons. This might be easier to acquire for your repair.

author: Nusa
author_rank: Super Contributor
timestamp: August 09, 2021, 07:46:16 am
content: In metal picture framing, they're called "spring clips" and are used in the same manner. Easiest way to get a few is probably just to buy a cheap picture frame at your nearest discount store. You likely need to cut them if you want them that short, but I suspect the longer version will work ok too.Alternately, you could use anything slightly compressible to serve the same purpose...you just need a fit snug enough to not rattle when you're done. Cardboard, cork, window gasket, etc.

author: tkamiya
author_rank: Super Contributor
timestamp: August 10, 2021, 01:39:15 am
content: I have lots of leaf springs for framing. I'll be glad to share some for the OP. However, those springs do not hold tight tension. I'm afraid they'll come lose and cause secondary problems.

author: m3vuv
author_rank: Super Contributor
timestamp: August 10, 2021, 10:01:00 am
content: what a fucking dumb question !,its not rocket science to work out you will have to make your own replacemts is by god!!

author: Nusa
author_rank: Super Contributor
timestamp: August 10, 2021, 10:37:20 am
content: Quote from: m3vuv on August 10, 2021, 10:01:00 amHaving a bad day? You know the old adage about if you can't say something nice...You might want to read this:https://www.eevblog.com/forum/chat/forum-rules-please-read/

author: tkamiya
author_rank: Super Contributor
timestamp: August 10, 2021, 12:29:12 pm
content: More I look at it, I don't think it's critical what you use. It's just a shim. Even a rectangular cut cardboard might work....
What is wrong with this EICO 430 oscilloscope? - Page 1
Forum section: electronics / repair

author: SLR
author_rank: Newbie
timestamp: July 26, 2020, 04:33:13 pm
content: All-I recently acquired an EICO 430 and have been have some “interesting” results which I hope you might help me fix.In the Horz/Ext mode using a simple curve tracer, I am getting a strange “golf club” end when testing diodes. (see photo attached). This only occurs only with diodes—the XY images using the same curve tracer testing capacitors and resistors look as expected. I thought it might be the tracer or my probes, but I tested the same diodes and curve tracer on other oscilloscopes and there was no “club”.My (very modest) electrical expertise suggests something (a capacitor?) is not right in the vertical circuit in the H/E mode, but I’m just guessing.Do you have any idea of the part or area I should look at and test?Much thanks for any help you can provide.SLR

author: bob91343
author_rank: Super Contributor
timestamp: July 26, 2020, 11:47:04 pm
content: Looks like some kind of hysteresis or phase shift. By hysteresis I mean, perhaps diode charge storage that causes the curve not to retrace itself. The EICO is a low end unit and I wouldn't trust it for much more than a general idea of what's going on.

author: floobydust
author_rank: Super Contributor
timestamp: July 27, 2020, 12:14:31 am
content: You have replaced ALL electrolytic capacitors in this almost 60 year old scope, right?Only three in the front end, and four as C14 in the power supply. They could cause a delayed trace shift or hum in the power supply. Only a few $ to change them out:C4 10uF 50VC5 10uF 150VC23 20uF 50VC14a 40uF 450VC14b 20uF 450V (might be 3 of 40uF on bom?)C14c 20uF 450VC14d 20uF 450Vedit: fixed scrambled image linkEico 430 1953 service manual here:https://elektrotanya.com/eico_430_3inch_25mv_500khz_10-valves_oscilloscope_1953_sm.pdf/download.html

author: CaptDon
author_rank: Super Contributor
timestamp: July 27, 2020, 01:10:33 pm
content: It looks like the bandwidth of your vertical channel istoo narrow. If the curve tracer uses a sawtooth sweepinstead of sine or triangle this problem occurs becausethe 'reset' part of the waveform is too fast for the scopeand it shows up as a hook or as phase shift. Somewhereyou are seeing the result of a delayed R/C phase shift.Are your probes 'compensated' to your scope using asquare wave input? I don't think the scope is bad, butinternally there may be compensation trimmer capacitorsto make square waves look square and you will find thatyour scope is out of adjustment showing either overshootor undershoot on square waves which will also causethat weird phase delay hook.

author: SLR
author_rank: Newbie
timestamp: July 30, 2020, 10:58:41 pm
content: Many thanks for all the helpful comments!

author: floobydust
author_rank: Super Contributor
timestamp: July 31, 2020, 04:22:12 am
content: Let us know if you find the problem
What is wrong with this spectrumanayzer HP8593A - Page 1
Forum section: electronics / repair

author: PA3BBV
author_rank: Contributor
timestamp: April 15, 2025, 06:52:53 am
content: Hi,I recently became a 22 GHZ spectrum analyzer from HP, the HP-8953A. At start up it shows the following screen. It seems to me not normal, what is wrong with it?

author: loulou31
author_rank: Contributor
timestamp: April 15, 2025, 07:26:41 am
content: Hi,All seems to be OK. Oven is cold because you have to wait about 5 mn. Noise level is higher at the end of frequency range because of the harmonic mixer.Jean-Louis

author: PA3BBV
author_rank: Contributor
timestamp: April 15, 2025, 08:06:33 am
content: Thank you Jean Louis for explaining the noise level difference. So there seems to be no problem.

author: pdenisowski
author_rank: Super Contributor
timestamp: April 15, 2025, 10:24:45 am
content: Quote from: loulou31 on April 15, 2025, 07:26:41 amYes, exactly this. You will see this "step" function in the noise floor / DANL on many spectrum analyzers, even modern / high-end ones.I actually mention in my video on DANLhttps://youtu.be/-2UTiDaIa5s?t=430

author: PA3BBV
author_rank: Contributor
timestamp: April 15, 2025, 11:46:53 am
content: Quote from: pdenisowski on April 15, 2025, 10:24:45 amThank You, I watched the video it helps by understanding
What kind of flex flat cable is this?  (for resistive touchscreen assembly)  - Page 1
Forum section: electronics / repair

author: naut
author_rank: Contributor
timestamp: July 01, 2019, 05:26:15 pm
content: Hello,I have a Cowon-D2 mp3 player and the flat ribbon cable (4 signal lines) that is connected to the resistive touch screen assembly has cracked, (shown with the red line) on the attached pic.Does anyone know what kind of flat ribbon cable is displayed in the picture?Or perhaps what resistive touchscreen overlay assembly model it is? The small text on the bottom reads "atouch ao25-3d e8". But I could not find such a touchscreen module.Thanks!https://www.cnet.com/products/cowon-d2/specs/https://ae01.alicdn.com/kf/HTB1n4vhzRyWBuNkSmFPq6xguVXaD.jpg

author: coromonadalix
author_rank: Super Contributor
timestamp: July 02, 2019, 01:07:17 am
content: For a touch overlay, You take the screen size meausrments and try to find a resistive or a capacitive overlay that match the screen sizehttps://www.ebay.com/itm/New-2-5-for-Cowon-D2-LCD-Screen-Display-Touch-Replacement-MP4-MP5-F8Y-/122964924419https://www.aliexpress.com/item/711203424.htmlhttps://www.aliexpress.com/item/32807059606.htmlhttps://www.dhgate.com/product/wholesale-cowon-d2-original-2-5-039-039-inch/403226103.htmlIt depends how much you want to pay ??

author: naut
author_rank: Contributor
timestamp: July 02, 2019, 09:22:13 pm
content: Phewww... It took me a while but I've fixed the cable. Not sure how long it's going to hold so I've ordered some 4 pin 1.0mm pitch flex cables just in case.Thanks for the links. I've seen the whole display assemblies but it's overkill in this case. As far as the overlays, I was not able to find out exactly the one that would fit the display module.

author: Nerull
author_rank: Frequent Contributor
timestamp: July 03, 2019, 01:46:41 am
content: Pretty sure that isn't a cable, its a flex pcb.

author: wraper
author_rank: Unknown
timestamp: July 03, 2019, 02:00:34 am
content: Quote from: Nerull on July 03, 2019, 01:46:41 amIt's FFC (Flexible flatcable)https://en.wikipedia.org/wiki/Flexible_flat_cable. Carbon traces on kapton substrate. Often also called FPC cable (flexible printed circuit) although it's technically not correct as there are no components.
What part is this? - Page 1
Forum section: electronics / repair

author: OutThere
author_rank: Contributor
timestamp: June 01, 2024, 02:11:33 am
content: it's from the PFC part of a switch mode power supply. it is across an inductor. the part number is SG7004 . I was thinking it's a Zenor diode, the silk screen part shows a box with a "G" inside. I used on a dvm the diode test , the display just stayed at open loop. i used one of those parts testers with a small LCD, said bad part , unknown part'

author: coromonadalix
author_rank: Super Contributor
timestamp: June 01, 2024, 02:15:19 am
content: gas tube discharge maybe ?

author: boB
author_rank: Frequent Contributor
timestamp: June 01, 2024, 02:19:39 am
content: Can you measure it ? Diode drop ? Resistance ?If low resistance, it might be a fuse

author: fzabkar
author_rank: Super Contributor
timestamp: June 01, 2024, 03:19:54 am
content: Spark Gaphttps://brightking.yageo.com/PRODUCTS/list_123.aspx?lcid=52https://brightking.yageo.com/uploadfiles/file/SPG/2021031418221622161050.pdfhttps://www.unictron.com/protection/circuit-protection-components/spark-gap-protectors-spg/

author: OutThere
author_rank: Contributor
timestamp: June 02, 2024, 01:14:15 am
content: please R E A D my post

author: OutThere
author_rank: Contributor
timestamp: June 02, 2024, 01:16:55 am
content: thank you for the info

author: tooki
author_rank: Super Contributor
timestamp: June 02, 2024, 12:12:06 pm
content: Quote from: OutThere on June 02, 2024, 01:14:15 amPlease learn to use the “quote” button so people know what you’re responding to. “Reply” simply adds a new reply to the end of the thread, with no further context or ability to show what it was in response to.
What should I use for securing components on PCB to give mechanical strength - Page 1
Forum section: electronics / repair

author: Yamin
author_rank: Frequent Contributor
timestamp: September 01, 2019, 09:43:52 pm
content: Hi everyone,I'm looking for a solution to secure components on a VOX amplifier, I am hoping to get suggestions that would be available from the local hardware stores.I have had bad experience with 'hot glue' it often gets dislodged.Some of the components I need to secure does get quite hot, not boiling hot! (couple of 5W resistors).The research I did on the internet points to natural cure silicon, and also I came across the term RTV, and a local technician suggest 'gasket silicon'. I got myself a bottle and I wanted to see whether it was conductive. I noticed that when applied it has a liquid-ish kind of consistency.I have included some pictures of the options I could find from the local hardware stores.Thanks in advance for the help.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 01, 2019, 09:59:13 pm
content: I think Silastic or equivalent competitor is the common solution.

author: 2N3055
author_rank: Super Contributor
timestamp: September 01, 2019, 10:06:20 pm
content: None of the silicone that smells like vinegar (acetic acid) should be used....Use some kind of flexible polymer based construction glue.

author: fourfathom
author_rank: Super Contributor
timestamp: September 02, 2019, 02:06:13 am
content: A polyurethane glue (like Gorilla Glue, or 3M 4200) might be appropriate. These are tough, but have a little flexibility. 3M 5200 is stronger, but not as compliant. I don't know about temperature range though.

author: tboy
author_rank: Contributor
timestamp: September 02, 2019, 05:15:54 am
content: Dow Corning (Dowsil) 3140 or 3145 is best. 3140 is more fluid.
What temp setting for trace/pad repair. - Page 1
Forum section: electronics / repair

author: Serge125
author_rank: Regular Contributor
timestamp: March 01, 2021, 06:38:18 pm
content: Hi all. I will be attempting to fix a tv main board for the first time and the problem is a very sloppy job that someone did before me and it broke the HDMI connection off the board taking with it is a few pads. I have a very old microscope that I bought a long time ago at a garage sale and it only has an eye piece but I can see clearly that yep I have about 10 missing pads. So since I don't have an air soldering station (yet) but I do have my new Hakko FX888D soldering iron. So what would be a good setting to fix the trace/pads without doing more damage. Any advice on my first time (oh I did fix normal size traces/pads a long time ago though) doing micro fixing? I will clean the pads (what's left of them) from the old solder and try to get some good contacts from traces.Thanks for all the help!!BTW here's a pic of my microscope that I will be using. ;-)

author: KevinA
author_rank: Regular Contributor
timestamp: March 01, 2021, 08:33:15 pm
content: Watch

author: Serge125
author_rank: Regular Contributor
timestamp: March 01, 2021, 09:37:46 pm
content: Quote from: KevinA on March 01, 2021, 08:33:15 pmOh this I CAN DO no problem but now I'm at microscope size fixing here btw 1982 didn't have much microscopic electronics like iphones and stuff. The traces are are as thin as hair and I just want to know IF there is a "special" way to fix microscopic traces compared to 1982 ways. Thanks for the video though!! ;-)Serge

author: Serge125
author_rank: Regular Contributor
timestamp: March 01, 2021, 09:57:49 pm
content: I just came across this on Amazon;https://www.amazon.ca/Conductive-Shielding-Repellent-Electrical-Grounding/dp/B07MFG98TV/ref=sr_1_6?dchild=1&keywords=Copper%2BTape&qid=1614635341&sr=8-6&th=1Is this any good to fix the pads?? I could put epoxy on the pads since I don't think the adhesive will stay there under heat. Any thoughts??Thanks!!

author: helius
author_rank: Super Contributor
timestamp: March 01, 2021, 10:02:41 pm
content: You get more consistent results using pad and trace repair kits, since they have the correct thickness of copper. They are available both without adhesive backing (so you mix epoxy, use masking tape to create a channel, and stick the new trace/pad to the board), or with heat-activated adhesive backing, which is faster.

author: Serge125
author_rank: Regular Contributor
timestamp: March 02, 2021, 02:34:14 pm
content: Gee where can I get this kit??

author: aqibi2000
author_rank: Regular Contributor
timestamp: March 02, 2021, 10:56:51 pm
content: Hdmi port trace repairs are easyHere’s an examplehttps://youtu.be/Et5pg5TbQIo
What the heck is this thing? - Page 1
Forum section: electronics / repair

author: Dave92F1
author_rank: Contributor
timestamp: October 21, 2023, 08:58:44 pm
content: I hope this is the right place to post this.I picked up this Soltec model VP-6414S X-Y chart recorder at a ham fest.This is what it looks like inside:It's an analog XY recorder (basically a XY pen plotter) from the late 1980s.It mostly works and I'm trying to restore it. But there's a mystery.There's a switch marked "CHART HOLD", which can be set to "HOLD" or "FREE". How the heck is that supposed to work? There's no obvious mechanism to hold or release the paper. And if I flip the switch, as far as I can tell nothing happens at all.There's compartment on the right which looks like it was designed to hold a roll of paper:On the top of the printing surface there's two yellow LEDs (they're on all the time the thing is powered), and no other obvious mechanism:I suspect the two LEDs were meant to shine thru the paper to help you line up the X and Y zero points for calibration. No mystery there.But if I look on the underside of the printing surface, I see this:The little PCBs hold the LEDs and series resistors. But what's under the RTV goop in the middle with the 2 wires going into it?I probed around on the top side with a magnet while flipping the CHART HOLD switch each way - nothing obvious.Both the LEDs and the mystery RTV thing plug in here, just to the right of the red high-voltage arrow shield:On that connector, the top 2 pins power the LEDs (about 14 VDC on them).The bottom two pins go to the mystery RTV thing. In the "FREE" position there's about 4 VDC across them (at extremely low current). But in the "HOLD" position there's about 1400 VDC across them (also tiny current).What's under the RTV, and how is it supposed to work?

author: DavidAlfa
author_rank: Super Contributor
timestamp: October 21, 2023, 09:02:25 pm
content: Maybe a Hall sensor or Reed switch to detect zero cross or calibrate the zero position?

author: TimFox
author_rank: Super Contributor
timestamp: October 21, 2023, 09:07:18 pm
content: On that type of unit, for use with thin graph paper ("onionskin" weight), there was often an electrostatic mechanism to hold the paper down after the user located it properly in the frame.I don't know exactly how that was built.

author: Gyro
author_rank: Super Contributor
timestamp: October 21, 2023, 09:47:01 pm
content: Yes, It looks as if it has an inverter for electrostatic hold-down on the bottom left of the PCB image (secondary under the black plastic with the High Voltage symbol). It should be current limited but watch your fingers! The hold-down is usually a set of interleaved PCB fingers underneath an insulating top sheet [EDIT: but might be a single plane and then a grid on a layer above it].

author: Gyro
author_rank: Super Contributor
timestamp: October 22, 2023, 08:37:33 pm
content: I knew I had it somewhere. Electrostatic paper holder article attached...

author: p.larner
author_rank: Frequent Contributor
timestamp: October 23, 2023, 01:29:40 am
content: if it was me that would be getting a 7w laser in place of the pen,teady made laser engraver.
Techinical Pro HB1502U rack mount amplifier How do I remove connectors to board - Page 1
Forum section: electronics / repair

author: onedumbquestion
author_rank: Contributor
timestamp: February 24, 2023, 12:34:12 am
content: I'm having trouble removing connectors from the board and also it seems to be missing a bracket to hold the front 1/4" jacks panel on so my questions are what's the missing part, I guess after I remove the board I'll find it underneath, and as you can see in the photo I pried up a connector and the nylon rose up leaving the pins exposed What's the right way disconnect those kind of connectors?https://imgur.com/a/8msXj0Dhttps://imgur.com/a/YFeYi3h
what thing/material to prevent solder go over neighbor - Page 1
Forum section: electronics / repair

author: abdulbadii
author_rank: Frequent Contributor
timestamp: December 08, 2021, 05:41:32 pm
content: How to solder tiny, tight, narrow pinhole and PCB layout, what thing/material to prevent solder to go over neighboring pin/hole ?Of course, means it must be little/non heat conductive to prevent draining soldering iron heat

author: coromonadalix
author_rank: Super Contributor
timestamp: December 09, 2021, 02:43:30 am
content: you could use Kapton tape or what we call "peel off" its made for electronics, its a kind of semi liquid foam (heat resistant solder resistant) you mask the things you dont want to be touched .... it will dry in 15-30 mins, do the job you want to do and after you can peel it offyou have some who can be washed off ... it will desintegrate with water
What this component name? I never seen before at my education - Page 1
Forum section: electronics / repair

author: RahmanID
author_rank: Contributor
timestamp: February 23, 2025, 08:23:02 am
content: Currently I'm working on WG Spectrum Analyzer, after checking some components found shorted to ground. But I don't know what exactly component name. (see this picture).In the schematic. Component with number "C215" when I probe their PIN have shorted to ground.But another component similar like that not shorted yet.Anyone know what exactly name of the component and what their function.Thank you.

author: wasedadoc
author_rank: Super Contributor
timestamp: February 23, 2025, 09:05:21 am
content: Feed through capacitor.In your case. 5nF as part of filtering on power lines into that shielded section.The capacitance is between the through wire and the metalwork it is soldered into. NOT between the two ends of the wire. They will appear as a short.

author: RahmanID
author_rank: Contributor
timestamp: February 23, 2025, 09:21:36 am
content: Quote from: wasedadoc on February 23, 2025, 09:05:21 amThank you.I have probe between start and end of wire to the ground.

author: wasedadoc
author_rank: Super Contributor
timestamp: February 23, 2025, 10:53:14 am
content: Quote from: RahmanID on February 23, 2025, 09:21:36 amWithout further evidence I would suspect the short to ground being elsewhere, not the feed through capacitor. Desolder the two ends of the through wire and make the three tests for the short.

author: RahmanID
author_rank: Contributor
timestamp: February 23, 2025, 02:13:32 pm
content: Quote from: wasedadoc on February 23, 2025, 10:53:14 amGood point!Will try it
What type of AC-connector is this (vintage cassette recorder) - Page 1
Forum section: electronics / repair

author: gronn-overledning
author_rank: Contributor
timestamp: August 21, 2024, 07:40:57 pm
content: Looking for a connector or cable for this old (german?) tape recorder ITT SL 55For an untrained eye, it may look like the IEC C7/C8 that has round pins, but its not...This is flat spade-pins.The tape recorder:https://duckduckgo.com/?t=lm&q=ITT+SL+55+old+cassette+recorder&iax=images&ia=imagesThanks

author: RoGeorge
author_rank: Super Contributor
timestamp: August 22, 2024, 08:54:57 am
content: I'll improvise from 2 individual female disconnect terminals crimped to the AC cable. Fit them one by one into the tape recorder's male receptacles (you might need to bend/shape the female plugs to fit just right), then pour bathroom-silicon on top and let it solidify, to form a socket.https://www.elecdirect.com/crimp-wire-terminals/disconnect-terminals-fully-insulated

author: gronn-overledning
author_rank: Contributor
timestamp: August 22, 2024, 10:30:38 am
content: Thanks. I would improvise myself, but this is for helping out some others with a cable.I know the risk of shorting or touching those pins when LIVE with AC 200V+, but should be a warning with thisStill want to know if this connector/cable has a name.

author: Haenk
author_rank: Super Contributor
timestamp: August 22, 2024, 11:10:36 am
content: Checked with the schematics on Elektrotanya - 2SB and 2SC in there, so this originates from Japan. I assume Crown or National Panasonic made.However, I know for a fact (as I tried to trace down some calculator power cables from that time earlier) that there often were customer specific styles of plugs used.So I assume this is a custom one.
What type of photodiode is this type? - Page 1
Forum section: electronics / repair

author: daisizhou
author_rank: Super Contributor
timestamp: March 20, 2023, 12:49:01 pm
content: The real object is the same as the picture,The working wavelength is 660nm/890-950nmIf you know the exact model, please let me know. Thank you for your help

author: CosteC
author_rank: Regular Contributor
timestamp: March 20, 2023, 08:08:46 pm
content: Photo is not great, but for me it looks more like photovoltaic cell, single one. Calculators have often 4 in series and you can see sections. Technically this is photodiode too - super large and slow. Filter on top may shift peak response wavelength. I am guessing only.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: March 21, 2023, 03:33:48 pm
content: Any device info ?

author: Kim Christensen
author_rank: Super Contributor
timestamp: March 21, 2023, 05:49:33 pm
content: Can you post a picture of the thing this is supposed to be sensing?Is it some sort of slotted wheel, and where exactly it is positioned relative to the sensors on the PCB?

author: daisizhou
author_rank: Super Contributor
timestamp: March 22, 2023, 12:27:51 am
content: It is a sensor inside the SPO2 analyzer

author: daisizhou
author_rank: Super Contributor
timestamp: March 22, 2023, 12:49:13 am
content: This is its user manualhttps://wetransfer.com/downloads/0fc1e683ddd4e9babf465fff50543aa320230322004753/15c2f0356def3403d8e07761ef0cad7220230322004811/16f587

author: james_s
author_rank: Super Contributor
timestamp: March 22, 2023, 01:13:13 am
content: It looks like a bare die, a silicon solar cell and a photodiode are pretty much the same thing. It's very possible that it's a custom part, is yours defective?

author: daisizhou
author_rank: Super Contributor
timestamp: March 22, 2023, 01:21:05 am
content: I would like to know the exact model, but the appearance is not marked

author: james_s
author_rank: Super Contributor
timestamp: March 22, 2023, 02:06:38 am
content: Well if it is a custom part then the exact model will be relevant only to the OEM. If it's not marked it will be extremely difficult to determine that for sure.

author: daisizhou
author_rank: Super Contributor
timestamp: March 22, 2023, 03:30:22 am
content: I checked my back just now, but unfortunately there was no sign,There is no model mark
What type of rs232 wiring is this? - Page 1
Forum section: electronics / repair

author: Chriss
author_rank: Frequent Contributor
timestamp: June 19, 2022, 10:19:53 am
content: Hi!I have to change a broken 9pin rs232 connector where the pin no 1,3 and 4 are broken, pulled out and the whole connector is crashed.I never saw such of type of connection where pin no 1, 3 and 4 are used.The device is a kind of "calibrator zurf" from a tractor.What type of wiring is this?I know the common type like gnd, rx and tx 3 wire connection.

author: Psi
author_rank: Super Contributor
timestamp: June 19, 2022, 10:46:41 am
content: It's probably not RS232 at all but some other signals using a DB9 connector.They aren't exclusively a connector for RS232.

author: Siwastaja
author_rank: Super Contributor
timestamp: June 19, 2022, 10:50:09 am
content: There is no such thing as "rs232 connector".It can be anything, only the user manual will tell what it is. If you can say which tractor (make/model) then maybe someone will chime in.

author: wraper
author_rank: Unknown
timestamp: June 19, 2022, 10:53:44 am
content: It could be RS-232 with a different pinout or something entirely different. For example Sartorius precision balances were notorious for using a different RS-232 pinout to sell cables at exorbitant price.

author: Chriss
author_rank: Frequent Contributor
timestamp: June 19, 2022, 11:02:50 am
content: The device is not tractor specific, it is also not an oem device.But yes, probably the main misunderstanding by me was/is that I saw the rs232 connector but probably the manufacturer use the gnd, rx,tx wires also but on a different pinout of the connector...
What type of terminal are these? From Dewalt 20v battery - Page 1
Forum section: electronics / repair

author: Chipson
author_rank: Newbie
timestamp: July 17, 2022, 04:57:32 pm
content: What type of terminal are these? From Dewalt 20v batteryI broke it and can't find this part online.

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: July 19, 2022, 02:19:48 am
content: Try Dewalt parts.Jeff

author: sleemanj
author_rank: Super Contributor
timestamp: July 19, 2022, 02:29:10 am
content: It's not going to be an off-the-shelf part.Simplest way would probably be to buy a dead pack from eBay/whatever and salvage it's connector (and at the same time likely salvage yourself some good 18650 cells).

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: July 20, 2022, 01:56:51 am
content: I guess I misunderstood, if this is the battery side and not the tool sideyou will have to find a battery for parts or as a replacement.Jeff
What value motor capacitor is this? - Page 1
Forum section: electronics / repair

author: Krudler
author_rank: Newbie
timestamp: December 05, 2021, 12:16:02 pm
content: The capacitor on my planer has failed, and the insides have leaked over the value of the capacitor. There is some informatin left visible - Anyone know what the value would be given this?Thanks

author: Andy Watson
author_rank: Super Contributor
timestamp: December 05, 2021, 01:11:30 pm
content: Is there a plate on the motor? What size/power is the motor?

author: themadhippy
author_rank: Super Contributor
timestamp: December 05, 2021, 01:21:02 pm
content: 30MFDhttps://www.radwell.co.uk/en-GB/Buy/FACON/FACON/7G72300N7L/

author: wraper
author_rank: Unknown
timestamp: December 05, 2021, 01:23:28 pm
content: Part number seems to be 7G72300N7B which suggests it's likely 30uF when looking on other capacitors from FACON.

author: Krudler
author_rank: Newbie
timestamp: December 05, 2021, 01:29:53 pm
content: Thanks guys - you are better Googlers than I am. I did look for other Facon caps, but couldn't find any consistency in that number system. It's a 3HP motor, 2.2kW.
What's a good potentiometer brand? - Page 1
Forum section: electronics / repair

author: tonylegrone
author_rank: Newbie
timestamp: March 24, 2020, 02:05:57 pm
content: Hi All,I'm looking for recommendations on a good potentiometer brand that I can get in the US.My friend got a DIY synth kit and asked me to assemble it for him. I got finished the build only to find that the pots it came with have faulty connections from the lead to the trace. The leads wiggle and the connection cuts out. All of them appear to be this way. The pots have no markings, but the BOM says they're BI Technologies / TT Electronics from Mouser (https://www.mouser.com/ProductDetail/BI-Technologies-TT-Electronics/P160KN-0QC15B100K?qs=%252BUYXD5bnyXqkOkKBeOUZcQ%3D%3D).I had a couple extra pots that I got from this website,https://guitarpedalparts.com/collections/solder-lugs/products/a100k-16mm-potentiometer-round-shaft-solder-lugs, made by Hongh that seem to be much higher quality (I've had no issues with them). Unfortunately, they don't have all the ohm ratings that I need for this project. The only other website I could find a full assortment of Hongh pots was a Belgian website and I'd have to wait for international shipping.Mouser and Digi-Key are the only domestic sites I know of that have a lot of options, but neither carry Hongh. I'm very inexperienced when it comes to parts manufacturers, so I thought it would be good to ask this community for help.Thanks in advance!Tony

author: jct
author_rank: Contributor
timestamp: March 24, 2020, 02:22:06 pm
content: Alps is a good brand, find the pot you are looking for on their website (https://tech.alpsalpine.com/e/category_potentiometer.html) look up the part # and search same on Digikey and/or Mouser.

author: rvalente
author_rank: Frequent Contributor
timestamp: March 24, 2020, 09:15:02 pm
content: First classSpectrolVishay BournsHoneywellhttps://sensing.honeywell.com/sensors/potentiometersNot so good but lower cost: ACP Technologies

author: edavid
author_rank: Super Contributor
timestamp: March 24, 2020, 09:38:03 pm
content: BI/TT is a decent brand - even though the model you list is not very expensive, it shouldn't be as bad as you describe. Also, they do mark their parts.The pots in the kit were probably generic pots from China that happen to look the same.Why don't you ask the kit supplier to replace the bad pots?

author: tonylegrone
author_rank: Newbie
timestamp: March 26, 2020, 01:34:13 pm
content: QuoteThat's a good point. It seemed like a hassle since I didn't order them myself and I assumed I would just get the same no-name parts again.I really appreciate you all taking time to help me out with suggestions!

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: March 27, 2020, 12:44:42 am
content: Quote from: tonylegrone on March 26, 2020, 01:34:13 pmWe're so lonelyGood luck.
What's the line voltage switch on a HP 6826A look like? (Mine may be missing it) - Page 1
Forum section: electronics / repair

author: py-bb
author_rank: Regular Contributor
timestamp: January 17, 2023, 05:51:06 pm
content: Hi there,I've just got a HP 6826A that needs repair. The first thing to check is that the line selection voltage is set. I believe mine is missing the switch. Below the fuse is a bit of circuit board with some pads on it - no switch.Could someone take a picture of the rear of theirs so I can see what it's supposed to look like to confirm mine's missing one please?Thanks

author: alm
author_rank: Super Contributor
timestamp: January 17, 2023, 07:11:44 pm
content: Can you post a picture of the pieces that you have? I believe some power supplies around that time used a piece of circuit board that you could pull out using a lever and rotate to change the voltage setting, and then re-insert. But there might well be different models.

author: py-bb
author_rank: Regular Contributor
timestamp: January 17, 2023, 11:56:54 pm
content: So it's got this cool little circuit board you pull out and rotate. I'll post a pic later! It took mea whileto figure that out!

author: srb1954
author_rank: Super Contributor
timestamp: January 18, 2023, 03:49:06 am
content: Quote from: py-bb on January 17, 2023, 11:56:54 pmThere will be numbers etched on the circuit board for the mains voltage selection. Orientate the circuit board so that your desired mains voltage setting is visible on the back of the circuit board when re-inserting it.

author: py-bb
author_rank: Regular Contributor
timestamp: January 20, 2023, 03:46:49 am
content: Quote from: srb1954 on January 18, 2023, 03:49:06 amYeah I got there in the end - I will post pictures because it took me ages. Schematic and then thinking "where's this switch?!" the manual literally says "and by default the switch is in the (up-arrow icon) position" and then moves on. Nothing about this little card you pull out.
What's the value of this 5L0F smd resistor?  - Page 1
Forum section: electronics / repair

author: Chriss
author_rank: Frequent Contributor
timestamp: November 04, 2019, 12:00:01 pm
content: Hi!I have a current sensing resistor in my circuit which is bad and the labeling is 5L0F.Can somebody approve the correct value?I was searching on the net and there come up different values.Thanks.

author: andy3055
author_rank: Super Contributor
timestamp: November 04, 2019, 06:56:39 pm
content: Here is a site where it has the option of putting the code and reading the real value. It is under the paragraph "SMD resistor calculator." The code you have does not come up with anything. Perhaps there is something on the other side?http://www.resistorguide.com/resistor-smd-code/

author: Chriss
author_rank: Frequent Contributor
timestamp: November 04, 2019, 07:06:25 pm
content: Nothing on the other side.Maybe it is a mask code for that part.

author: PA0PBZ
author_rank: Super Contributor
timestamp: November 04, 2019, 07:09:46 pm
content: https://www.aliexpress.com/item/32363312686.html

author: JackJones
author_rank: Regular Contributor
timestamp: November 04, 2019, 07:16:36 pm
content: http://www.ibselectronics.com/ibsstore/datasheet/wsl%20(3).pdfQuoteHow do you know they're bad?

author: Chriss
author_rank: Frequent Contributor
timestamp: November 04, 2019, 08:24:23 pm
content: No reading when I test for continuity with my dmm.

author: tru
author_rank: Regular Contributor
timestamp: November 04, 2019, 08:26:04 pm
content: Perhaps this:https://www.digikey.co.uk/product-detail/en/vishay-dale/WSLP25125L000FEA/541-10153-1-ND/9758590https://uk.farnell.com/vishay/wslp25125l000fea/current-sense-res-0r005-1-3-w/dp/2420770?st=WSLP25125L000Package size: 2512 (imperial inch), 3W, 1%, 0.005ohmsYou'll have to measure the width and length to find out whether 2010 or 2512 (imperial)
Whelen strobe power supply repair - Page 1
Forum section: electronics / repair

author: rhythmtone
author_rank: Newbie
timestamp: April 09, 2025, 07:47:36 am
content: Hi,I have a Whelen strobe power supply/controller on a vehicle (12v circuit) - Model UPS-54C.It stopped working recently, upon opening the case the main capacitors are clearly leaking and have failed. Searching reveals they are 200uf 360V - not super easy to find and/or expensive, and near impossible to find screw terminal type for any reasonable price.Any advice on fixing this would be greatly appreciated, I have the following plan:Images of existing unit:https://photos.app.goo.gl/Vy4xSHpUFGZy1Vvy7Link to OEM cap (specs, model #, etc) - unobtainable:https://shop.boeing.com/aviation-supply/p/51-3361201-42=3YReplacement part:https://www.mouser.com/ProductDetail/Nichicon/UTH2G201MND?qs=jRuttqqUwMRVG4J0li3Gkg%3D%3DQuestions:This seems like the correct part, 200uf 400V, but if anyone can recommend another part that might be better, that's fine.Can I cut the wire terminals and solder directly to the new caps? I was hoping to use shrink wrap terminals with integrated solder (sleeve).They have the caps in series, with a plate joining them - will 14AWG be a sufficient replacement for this? Main fuse for the unit is 10A.Thanks!
When I heat the PCB, the voltage becomes constant. - Page 1
Forum section: electronics / repair

author: sncnal
author_rank: Newbie
timestamp: May 25, 2022, 03:18:19 pm
content: Hi everyone. I have a question for you. I've Lınak motor controller PCB. This PCB was working 3.3 voltage not became constant. This value has changed between 2.8 - 3.3 at begin. After 10 min. later this voltage became constant. I checked all soldering part IC components. I never found trouble on PCB.I noticed a pic of the PCB and the location indicated by the green circle this location when I was hit with a hot gun this place the PCB worked as well.Thank you!https://www.hizliresim.com/h2oha56

author: unknownsoldier90
author_rank: Contributor
timestamp: May 25, 2022, 06:36:33 pm
content: Electrolytic caps could be bad

author: t1d
author_rank: Super Contributor
timestamp: May 28, 2022, 08:07:02 am
content: Use a wooden stick to push on the components and PCB in that area and see what changes. It may be just as easy to resolder ("reflow") all the solder joints on the components in that area. Also, check closely for a crack in the PCB, or a trace. Please remember to post your solution, when you find it.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 28, 2022, 12:15:51 pm
content: I have worked on a lot of things with your particular problem. Pushing on the board with a stick sometimes helps but you flex the board and the problem may be across the board and somehow the pressure you put on this part of the board will fix the problem that is really elsewhere. I still do the stick thing, even if it is not perfect.There could be a solder failure on one of the components or a microscopic crack on a trace.Here is what I would do:Re solder the caps, if the solder looks bad, remove it and re solder. Sometimes the through hole connections on these connections are not good and the solder does not reach the top of the board from the bottom, where you solder it.Look for small cracks on the traces and surface mount component solder joints with high magnification.Replace the caps (cheap enough)It is possible that one of the surface mounted components is the problem, but less likely than just a bad connection.

author: mariush
author_rank: Super Contributor
timestamp: May 28, 2022, 06:16:19 pm
content: Remove that light brown "glue" that's used to hold the electrolytic capacitors, sometimes that material can absorb humidity and become slightly conductive.It can also hide electrolyte leaking from the bottom of the capacitor or from the top.Inspect components and make sure there's no bad solder joints.