hybridfree/eevblog-posts huggingface dataset:
Replacing Blitzwolf BW-VP6 LCD - Page 1
Forum section: electronics / repair

author: hbt
author_rank: Contributor
timestamp: February 02, 2021, 04:08:14 pm
content: Hello, everyone.I know this may be a long shot, but I have a Blitzwolf VP6 projector which has an LCD with a broken flat cable. As I don't possess the tools which may allow me to flux and solder such tiny flat cable contacts, I was thinking about replacing the entire LCD.My main problem is identifying the LCD itself, since it's a 5.5 inches Full HD, no backlight LCD, as expected for a video projector, so, no labels on the LCD itself. The only reference I have is on the flat cable itself, which is FPC-ND598NI00-V0.I'd like to know, if someone can help me out, either identifying the LCD panel or the type of connection for the LCD so I can try to find a compatible one. I'm afraid of purchasing some 5.5 inches LCD that won't work properly with the projector driver, which is onboard.I'd appreciate any help someone may be able to give me on this matter.Best regards.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 02, 2021, 11:42:03 pm
content: Hi you should add your country in your profile, and maybe near you you could find a tech who could poke in your projector and try to identify the lcd

author: hbt
author_rank: Contributor
timestamp: February 06, 2021, 01:20:58 pm
content: Thanks for the feedback.I'm from Portugal.As the LCD doesn't have any reference number except for the flat cable and the brand isn't getting back to my email requests, I can't even tell what is the interface they use.As for the repair, I'm able to replace the LCD without a problem. It's not a big deal. But in Portugal, no one I talked about can identify the LCD, so I was hoping to get someone to give me more hands on experience on solving this matter.The LCD is as in the attached pictures.Thank you for the input.

author: erickcouto
author_rank: Newbie
timestamp: February 01, 2022, 11:16:06 pm
content: Conseguiu algo amigo? o meu ficou ruim também! sou do Porto

author: fabiostx
author_rank: Newbie
timestamp: June 01, 2022, 01:16:21 pm
content: Olá, tudo bem? Voce conseguiu? O meu tambem ficou ruim e nao estou encontrando para comprar. Pode me ajudar por favor? Obrigado!
Replacing board mounted USB B mini connectors with USB C - Page 1
Forum section: electronics / repair

author: aprusek
author_rank: Newbie
timestamp: May 13, 2024, 10:42:42 pm
content: Has anyone have any luck finding pin compatible USB C connectors that can be used to replace USB B mini connectors?

author: wraper
author_rank: Unknown
timestamp: May 13, 2024, 10:50:30 pm
content: Forget about it, there aren't and cannot possibly be.

author: thm_w
author_rank: Super Contributor
timestamp: May 13, 2024, 11:21:46 pm
content: If you have space use chassis mount insteadhttps://www.aliexpress.us/item/3256806789033499.htmlsnap inhttps://www.aliexpress.us/item/3256806753403420.htmlscrew inhttps://www.aliexpress.us/item/3256806084688866.htmlroundhttps://www.aliexpress.us/item/3256805945099380.htmlpower onlyMaybe could epoxy a break out module to the pcb, not a great option though.

author: ataradov
author_rank: Super Contributor
timestamp: May 14, 2024, 12:57:00 am
content: It is not even theoretically possible to make a generic replacement that needs data transfer. Assuming only one device role and no OTG support, it would be possible, but there is no chance anyone would make anything like this. Especially for this relatively rare through hole package.And even with the linked connectors you would still need CCx resistors, which makes the whole thing messy.

author: thm_w
author_rank: Super Contributor
timestamp: May 15, 2024, 12:10:53 am
content: Some of them include CCx resistors.Here is even one with LEDs too:https://www.aliexpress.us/item/1005006640650907.htmlIf its just for charging its not messy at all, very simple.
Replacing caps on HP 54522a SMPS - Page 1
Forum section: electronics / repair

author: Tim T
author_rank: Contributor
timestamp: March 19, 2022, 01:25:42 pm
content: One of the 2200uF 50v electrolytics on the secondary side of the SMPS in my HP 54522A scope decided to blow the other day, and on inspection other caps were leaking as well. The power supply is a Computer Products XL130-3630E from 1993, no schematic/specs can be found, the HP service manual just says to replace the entire unit, which of course is not much of an option today. So my thinking is to change out all the electrolytics on the secondary.Not having worked on SMPS previously, a bit of guidance on cap selection would be appreciated, this appears to be a complex topic with many conditional statements. Would using caps marketed as “suitable for switching power supplies”, such as Nichicon UPA series, be appropriate for the entire secondary, or are there some traps where a low ESR/high ripple current rating should be avoided. I suspect any general purpose 105C rated electrolytic would be OK on the primary side if deciding to replace them as well.Thanks, tim

author: rjmusto
author_rank: Contributor
timestamp: March 19, 2022, 07:03:46 pm
content: Hi Tim,I would not worry too much about it, just make sure you use good quality caps - cheap ones aren’t a good idea.Also check the main switching transistors are not short circuit and the all the main rectifiers are still good. I would also switch it on first time with a light bulb in series with the mains (an old fashioned incandescent type). That way you won’t create smoke if there is still a fault.Ralph

author: Tim T
author_rank: Contributor
timestamp: March 20, 2022, 02:24:32 am
content: Thanks Ralph.The leaking cap resulted in a dead short of -5.2v supply to ground, blasting a nice hole in the PCB that will be fun to repair.I was able to power down the scope within a few seconds of the failure, neither the mains line fuse or the fuse on the power supply board failed, hopefully no other damage happened.So yes, dim bulb tester and variac will be used when powering up the SMPS after recapping.tim

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 20, 2022, 05:17:33 pm
content: Generally speaking, more ripple current rating=more better. Meet or exceed installed temp and voltage rating.
Replacing damage RCA jacks on amplifier - Page 1
Forum section: electronics / repair

author: klausman
author_rank: Regular Contributor
timestamp: April 09, 2025, 10:29:15 am
content: So I have this otherwise fine Marantz PM-62 that "somehow" lost the sleeves on its tuner input:Rear view:Bottom view:As far as I can tell, every manufacturer just YOLO's the PCB-side pinout of these (plus, these seem to mount with a higher offset from the PCB than usual), I'm a bit out of ideas. Since the broken jack is in a cluster of three, I can't transplant another jackset (e.g. the remote control ones, that I don't care about).So what are my options? As far as I can tell I have thsese:Try and yank the sleeve off a donor jackset and hope it can be made to fitunsolder the 3x2 set, saw off the broken ones, replace with:panel mount jacks & wire2x1 stereo jacks that I get to mount "somehow"I think 2.1. is the most credible, but I am keen to hear other alternatives.Here's the other PCB with two 2x2 clusters (tape in/out) and the remote control 2x1 cluster:

author: elektryk
author_rank: Regular Contributor
timestamp: April 09, 2025, 11:29:42 am
content: Buy usual RCA block and connect it to the PCB with wires.
Replacing foam padding in Fluke 189 battery compartment - Page 1
Forum section: electronics / repair

author: beowulfenator
author_rank: Contributor
timestamp: July 25, 2020, 10:34:18 pm
content: Just bought a Fluke 189 from ebay, opened the battery compartment, and found that the foam padding in it turned to goo. I was able to get all of it out using alcohol.The question is, what should I replace it with so that it does not deteriorate in the next few years? Without the foam the unit is running fine, but i'm afraid that the batteries may become loose in the compartment.

author: retiredcaps
author_rank: Super Contributor
timestamp: July 26, 2020, 01:01:53 am
content: On modemhead's blog, I believe he just used double sided tape and cut his own padding.http://mrmodemhead.com/blog/gallery/fluke-189-clean-up/If you click on F189_028.JPG, it will say "New battery cushion strip installed."

author: retiredcaps
author_rank: Super Contributor
timestamp: July 26, 2020, 01:03:18 am
content: PS. I recommend using Eneloops vs alkaline batteries. Or if you use alkaline, check them every 3 months for leakage.https://www.panasonic.com/global/consumer/battery/eneloop.html

author: beowulfenator
author_rank: Contributor
timestamp: July 26, 2020, 09:08:14 am
content: Thank you! I see the battery cushion strip, but what is it made of?As for eneloops, they are rechargable, right?

author: coromonadalix
author_rank: Super Contributor
timestamp: July 26, 2020, 01:48:41 pm
content: i used door seal tape band on my 18912 mm width, choosen one with 5mm thickness up to this day it did not melt since its made for harsh environments

author: retiredcaps
author_rank: Super Contributor
timestamp: July 26, 2020, 07:51:44 pm
content: Quote from: beowulfenator on July 26, 2020, 09:08:14 amSee suggestion from coromonadalix in post below.QuoteYes, they are rechargeable LSD nimh. I use them in my 187 with no problems. I like using the 187 with backlight so I don't care how much battery life I use because I can just recharge them and I always have fully charged sets available if I run out.Eneloops are also rebranded by others. One for example is Ikea Ladda's. Seehttps://eneloop101.com/batteries/rewrapped-batteries/Look for Made in Japan.I have "real" eneloops, Duracell and Ikea rebranded. All are Made in Japan.
Replacing keypad HP8563a - Page 1
Forum section: electronics / repair

author: pe2ben
author_rank: Contributor
timestamp: April 18, 2022, 11:24:41 am
content: Hello everyone,Is it possible tot replace the rubber keypad from my 8563a with the keypad from a 8563E?Thanks, Ben

author: m k
author_rank: Super Contributor
timestamp: April 23, 2022, 06:30:29 pm
content: If it is just a skin with actual connection parts and mechanically fit then why not.
Replacing MELF resistor - Page 1
Forum section: electronics / repair

author: XaviPacheco
author_rank: Regular Contributor
timestamp: July 07, 2019, 07:47:04 pm
content: There's an array of 10 MELF resistors arranged as a voltage divider for high DC voltage sensing. All of the resistors are 400k (1/4W or 1/2W not sure). One of them is open. I'm trying to find the same replacement in Mouser/Digikey but I don't see them available. The closest one I saw was 402k but they are non-stocked. What do you suggest in this case? Using another package? The board is pretty delicate, that's why I'm trying to find the same replacement in order to avoid doing some ugly tweaking.

author: shakalnokturn
author_rank: Super Contributor
timestamp: July 08, 2019, 12:00:59 am
content: How delicate is your board?What tolerance do the original resistors have?The board must be very delicate if you need to worry about a +0.05% up.Assuming the resistors are all series and the one you're replacing is not the divided output one, I'd just throw the 402k in...

author: XaviPacheco
author_rank: Regular Contributor
timestamp: July 08, 2019, 12:30:10 am
content: Quote from: shakalnokturn on July 08, 2019, 12:00:59 amYes, all of them are in series. The 402k is non stocked. What about 392k?

author: jaromir
author_rank: Unknown
timestamp: July 08, 2019, 06:40:25 pm
content: 392k is 10k lower, but you may compensate it by removing another 402k resistor from string and replacing it with 412k resistor, so that total resistance of string will remain the same. 412k resistor will have a few percent higher power loss and voltage across it; but any sensible design should be de-rated so it shouldn't matter much.412k in E96 series too, so you may be lucky and find it in stock. If not, you may try to find another combination, but do not deviate much from 402k, because of voltage across resistors and power loss.

author: XaviPacheco
author_rank: Regular Contributor
timestamp: July 09, 2019, 04:23:59 pm
content: I'm having hard time trying to find those MELF resistors 400k, 0204 size. Can't I just use SMD chip resistors? 1206 size maybe?

author: capt bullshot
author_rank: Super Contributor
timestamp: July 09, 2019, 05:05:43 pm
content: Depends. Ten MELF resistors in series might form some kind of rugged high voltage divider chain, in which case I would recommend against replacing them with 1206 chip resistors since these aren't as robust as MELF.

author: eliocor
author_rank: Unknown
timestamp: July 09, 2019, 10:30:44 pm
content: Is it for a photomultiplier dynodes voltage divider?Buy 10 pieces of the nearest value ones (392k or 402k or ...) and replace ALL of the resistors in the voltage divider. The ratio will be the same!Also follow what capt bullshot says.

author: langwadt
author_rank: Super Contributor
timestamp: July 09, 2019, 10:48:57 pm
content: Quote from: shakalnokturn on July 08, 2019, 12:00:59 am0.5%but yeah unless the original was 0.1% it is likely good enough
Replacing polystyrene caps in an amp's protection circuit - Page 1
Forum section: electronics / repair

author: klausman
author_rank: Regular Contributor
timestamp: August 18, 2025, 02:22:49 pm
content: So I am repairing a Luxman LV-103 amplifier that won't come out of protection. I've repaired the broken bits (short on the speakers; blown output MOSFET), but while the protection board protected the speakers, it seems to have self-sacrificed: there are four polystyrene capacitors on it, one of which is completely gone, aside from its legs, one of which has a scorch mark (likely from the gone one) and the other two test as open circuit. Polystyrene caps are not made anymore, so I wondered what to replace them with. Physical size is not much a problem in thehorizontal,but I have maybe 10-15mm vertical space due to how the board is mounted. Neither the caps nor the service manual specify anything but capacitance (1200pF), so I'd probably go with something 100V if I can get away with it. 63V might also work but I am unsure if that's enough "headroom".Here's the schematic of the protection board, with the caps marked in red (note: this is not the entirety of the protection circuitry in the amp):I'd include the service manual, but it's too big to be attached here. It can be easily found on ET or HE.

author: TimFox
author_rank: Super Contributor
timestamp: August 18, 2025, 02:28:28 pm
content: A reasonable replacement for unobtainable polystyrene capacitors is polypropylene film, with similar electrical properties, higher temperature ratings, and comparable dimensions. For critical applications, polypropylene is better than polyester/MylarTM/PET film for dielectric loss and absorption.

author: edavid
author_rank: Super Contributor
timestamp: August 18, 2025, 03:03:49 pm
content: Since these caps are not in the audio path, wouldn't polyester (or even ceramic) be fine?

author: wraper
author_rank: Unknown
timestamp: August 18, 2025, 03:28:18 pm
content: NP0/C0G ceramic or any type of film capacitor.
Replacing shields on phone boards? - Page 1
Forum section: electronics / repair

author: FireHazard
author_rank: Contributor
timestamp: August 12, 2023, 11:35:52 pm
content: I've managed to "repair" a water damaged mobile phone (corrosion removal mostly), but I had to remove a number of metal shields on the main board. These shields were soldered on, I removed them by heating a pulling them off with tweezers.None of the resources I've found cover how to replace these shields...is it just a matter of putting them back in place, heating them and hoping for the best?.....

author: coppercone2
author_rank: Super Contributor
timestamp: August 13, 2023, 04:46:27 am
content: if they have a flange you can trim the flange very slightly to expose some pad so you can see the solder bead. Might be tricky with a phone or impossible, then you are left with intuition only.

author: FireHazard
author_rank: Contributor
timestamp: August 14, 2023, 07:20:03 am
content: Yeah....it's all so small...my biggest concern is shorting things under the shield ... since it's a fixed phone now...restored from failure, if it doesn't work correctly without the shields then still I'm in no worse state and have gained some new information.

author: coppercone2
author_rank: Super Contributor
timestamp: August 15, 2023, 12:23:08 am
content: you can stick up some flux to make it tacky, line the bottom of the shield, then get a very thin solder strand and line the bottom, then press and heat, like making a sandwich. You can meter it very carefully this way.I think they have solder down to 0.2 mm or whatever, so you can pick which one you think has the correct coverage.tinning it to make absolutely sure there is no squeeze out might actually be harder because its hard to tell how much solder there is, but if you clean the flange with braid so its solder free, then line it with solder, you can control it better, maybe.Or you MAYBE can get solder preform sheet, that is very thin, and cut a 'gasket' out of 4 pieces to line the bottom of the shield. Or run solder through a roller lol
Replacing the Rifas on a HP E3631A? - Page 1
Forum section: electronics / repair

author: knotlogic
author_rank: Regular Contributor
timestamp: July 12, 2020, 08:15:03 am
content: A while ago I cracked open my E3631A for a cleaning and to check out a problem, and noted that it had 3 Rifas on the AC input: A 0.1 uF X2 and 2 1 nF Y2 caps. I recall moisture ingress is suspected to be related to their rapidly exothermic end of life characteristic, and I live in the humid tropics, so I reckon I'd better replace them.The X2 cap is labeled PME 271 M. Assuming nothing's changed in the model line up, it has a lead spacing of 20.3 mm, and searching Mouser and Digi-Key, there are only 2 parts that will fit. A Kemet/Rifa PME271M, or a X1 rated PME271E. I suppose I don't have much choice, and either of these will do. Are the newer Kemet owned parts likely to eventually pop like their older counterparts? And does it mater which one I pick?With the Y2 cap, I can't read what's printed on the sides, but I suspect they're Rifa PME271Y caps, with a lead spacing of 10.2 mm. It looks like my only option for those are modern Kemet/Rifa PME271Y parts. Like the X2 cap, I'm wondering if these new ones are any better.Thoughts and advice welcome!

author: tggzzz
author_rank: Super Contributor
timestamp: July 12, 2020, 09:04:15 am
content: How old are the capacitors?Are there any visible cracks or crazing?When I replaced the RIFAs in my HP8562, I used new RIFA components. Principle: even if the new construction has the same flaws, they will outlast me.

author: knotlogic
author_rank: Regular Contributor
timestamp: July 12, 2020, 09:40:41 am
content: No idea on age, but the unit is HP branded, and Agilent was spun off in 1999? So a minimum of 20 years might be a safe bet.The X2 cap has a few cracks in it. Nothing as bad as some of the pictures I've seen posted here. The insides don't have a uniform appearance, they seem.... blotchy? I can't get a good angle to look at the Y2 caps, but the top of one might have a fine crack in it.

author: Haenk
author_rank: Super Contributor
timestamp: July 12, 2020, 11:11:53 am
content: The problem only arises, when the unit has not been powered on for quite some time. If it's stored dry and warm or is running on a regular base, no moisture accumulates and they won't explode.I would still replace them immediatly, as it's a ticking time bomb; maybe not for you, but the next owner.

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: August 16, 2020, 06:24:14 am
content: Go look at my discussion at:https://www.eevblog.com/forum/testgear/check-your-rifa-caps-in-your-agilent-bench-power-supplies-and-lessons-learned/msg2885786/#msg2885786I replaced all my RIFA cap at all my Agilent power supplies (one HP branded), with the vast majority of them in perfect condition. If you see cracks, it makes no sense to leave compromised $1 parts in your power supply and wait for it to blow and spill its guts.

author: bd139
author_rank: Super Contributor
timestamp: August 16, 2020, 09:10:07 am
content: Cracks means it could blow up next week. Replace them. Vishay and Epcos make equivalents which have no history of exploding.
Replacment touch screen for LeCroy 44Xi 64Xi 104Xi 204Xi - Page 1
Forum section: electronics / repair

author: perdrix
author_rank: Frequent Contributor
timestamp: July 03, 2021, 12:14:21 pm
content: Does anyone know what the touch screen is for the early Waverunner Xi 'scopes? Are the obtainable?I would appear that the touch screen is a separate part that sits on front of the LCD.ThanksDavid
Reproducing cable for dental handpiece, viability check - Page 1
Forum section: electronics / repair

author: zzattack
author_rank: Regular Contributor
timestamp: October 06, 2024, 04:06:11 pm
content: In trying to get an older medical (dental) device up an running, I have found that the cable connecting the control unit to the handpiece is faulty. It is a fairly simple unshielded 4-conductor cable. Despite a simple conductivity test passing just fine, I have isolated the issue to be with the receptable part which plugs into the handpiece by cutting up a known-good cable and cross-matching both ends.I'm trying to determine if this might be an off-the-shelf part (which I doubt), or if it could be economically reproduced by hand in small quantity. I have cut up one of these and found a small PCB which seems used only to connect the female gold pins to the 4 wires. The entire plug appears to be cast in a very hard material. It does not look like an off-the-shelf part to me. I have attached pictures of both the cable end as well was the part of the handpiece where this slots in.For recreation, I would need to find suitable silicone 4-conductor cable, matching receptable gold pins, and probably mount them on a small PCB. Next, I would need to enclose it to form a similar cylindrical shape, e.g. with two 3d-printed parts, and solidify the end result so that it mates properly with the handpiece.Does this seem viable, or would a different approach make more sense?

author: Haenk
author_rank: Super Contributor
timestamp: October 06, 2024, 06:07:27 pm
content: As you are nullifying the certification of the device with self-made parts anyway, why not replace both ends?

author: amyk
author_rank: Super Contributor
timestamp: October 06, 2024, 11:08:32 pm
content: Looks like some sort of drill? The other end of the connector is built into the handpiece.

author: zzattack
author_rank: Regular Contributor
timestamp: October 07, 2024, 07:02:01 am
content: Yep, so the shape of the plug is fixed.The handpiece supports different attachments, including a drill indeed.
Request for R&S SMIQ06B control board drawings (also used in SMP/SME/SMT) - Page 1
Forum section: electronics / repair

author: hazzer
author_rank: Regular Contributor
timestamp: June 17, 2024, 02:27:57 pm
content: EveningI'm searching for R&S drawings of the control / CPU board of my SMIQ06B , board part number 1084.8804.12. rev 05my unit halts on boot up with "access fault at E0182FF4h" and a "system halt".It my understand that the board is also used in SMP / SME / SMT generators (though perhaps not rev 05).Hoping someone can help.73Harry
Request for Service Manual or Documentation for Rohde & Schwarz LAS344.4010.02 - Page 1
Forum section: electronics / repair

author: UCY7400
author_rank: Newbie
timestamp: October 14, 2024, 01:12:46 pm
content: Hello,I am looking for the service manual or any technical documentation related to the Rohde & Schwarz logic analyzer model LAS344.4010.02. I’ve searched online but haven’t been able to locate specific information on this particular model. If anyone has access to the service manual, datasheets, or any relevant documents, I would appreciate your assistance. Alternatively, if you could guide me on where to find these resources, that would be really helpful.Thank you in advance! [ Attachment Invalid Or Does Not Exist ]

author: squadchannel
author_rank: Frequent Contributor
timestamp: October 14, 2024, 01:44:45 pm
content: Rohde was making LA?First time I've heard of it. I am curious.Might be quicker to ask him.pdenisowskiThe attachment seems to be invalid, is it an image?

author: Harry_22
author_rank: Frequent Contributor
timestamp: October 14, 2024, 07:48:09 pm
content: Hi!It looks like this is exactly the missing picture.
Requested: Hameg HM8115 Service Manual or circuit diagram - Page 1
Forum section: electronics / repair

author: rob040
author_rank: Contributor
timestamp: October 20, 2023, 03:40:13 pm
content: Hi,Can one of you help me getting the SM of the Hameg HM8115 power meter?Regards, Rob

author: TaylorD93
author_rank: Regular Contributor
timestamp: November 26, 2023, 04:10:10 pm
content: Hi Rob,I too am after this, did you have any luck?Thanks, Taylor

author: rob040
author_rank: Contributor
timestamp: November 26, 2023, 05:24:10 pm
content: Hi Taylor,Unfortunately not. Still on the wish list. :-)BR, Rob

author: satcom
author_rank: Newbie
timestamp: November 29, 2023, 09:30:03 am
content: Τhe service manual for the 8115-2 that exists at Elektrotanya does not work for you?

author: kripton2035
author_rank: Super Contributor
timestamp: November 29, 2023, 11:18:27 am
content: Quote from: satcom on November 29, 2023, 09:30:03 amit is the user manual, not the service

author: rob040
author_rank: Contributor
timestamp: August 20, 2024, 02:33:56 pm
content: Well, after so many months it's obvious that a service manual is at least one bridge too far.Let me narrow down my question: Does anyone of you have the adjustment procedure available? It's probably also described in the SM.There are 7 trimmer resistors (one is related to the monitor output) and one jumper that probably has to be used at some point.

author: djsb
author_rank: Super Contributor
timestamp: August 20, 2024, 03:12:00 pm
content: Have you tried contacting R&S directly? They may have archived information that they are willing to share. There is also maybe someone from R&S who posts on here now and then.

author: rob040
author_rank: Contributor
timestamp: August 20, 2024, 03:50:14 pm
content: Quote from: djsb on August 20, 2024, 03:12:00 pmI did and without success. I also tried Sky Messtechnik in Germany several times, but also they won't or can't give it to me.

author: djsb
author_rank: Super Contributor
timestamp: August 21, 2024, 06:29:18 pm
content: This group may be able to helphttps://groups.io/g/Hameg

author: rob040
author_rank: Contributor
timestamp: August 21, 2024, 07:21:12 pm
content: Hi David,Thank you for pointing me in that direction.But, I'm an active member in that group and did ask for it some months ago. Also no luck so far. :'(Best, Rob
Requesting Firmware for XL4005 step-down module with display (mcu stm8s103f3p) - Page 1
Forum section: electronics / repair

author: nour
author_rank: Frequent Contributor
timestamp: July 18, 2020, 06:37:21 pm
content: I have one of those buck converter modules with V/A display and until recently, the display module stopped working, after investigation, I found that the display onboard mcu was burnout and I have a replacement but I of course do not have the firmware.Does anyone have the firmware for this module or have the module and was able to get the firmware binary from the mcu ?It looks exactly like this onehttps://www.karosium.com/2015/10/random-teardowns-xl4005-5a-step-down.html#comment-formThe mcu is stm8s103f3p!
Require repair service for Keithley 2410's Analog board and digital board - Page 1
Forum section: electronics / repair

author: anupong1983
author_rank: Contributor
timestamp: September 01, 2022, 08:44:34 am
content: Hello Everyone,Who do a repair's service of Keithley 2410 (Failure: defective Analog board and digital board).Please contact me via email: anupong.j@vela.co.ththank you.
resealing curcuit boards - Page 1
Forum section: electronics / repair

author: Stori
author_rank: Contributor
timestamp: September 21, 2025, 11:41:52 pm
content: Hi guysI repaired a board that had broken circuits on it. I had to remove the coating in some places and now I need to reseal it, so it does not oxidize etc.Which products are recommended for this?Thanks

author: Kean
author_rank: Unknown
timestamp: September 22, 2025, 12:24:23 am
content: Conformal coatinghttps://en.wikipedia.org/wiki/Conformal_coatingI'd start by looking at options from Electrolube or MG Chemicals - or whatever similar brands are available locally to you.Which one is suitable depends on many factors, primarily level of protection and compatibility with the existing coating.Cost and method of application are also likely important if you don't have prior experience.Also, what environment is this being used in that oxidisation is a big issue? High humidity or marine use? Normal office/residential probably doesn't require it unless the voltages are quite high.

author: themadhippy
author_rank: Super Contributor
timestamp: September 22, 2025, 12:32:54 am
content: cheapskate option,clear nail varnish

author: Haenk
author_rank: Super Contributor
timestamp: September 22, 2025, 06:49:18 am
content: KONTAKT Chemie PLASTIK 70Available at most electronic shops, Amazon and ebay.Might be a bit expensive at 20,- EUR for a one-time use though...

author: Smokey
author_rank: Super Contributor
timestamp: September 22, 2025, 06:51:36 am
content: How about solder? Tin the exposed copper and you should be good.

author: 2nOrderEDO
author_rank: Regular Contributor
timestamp: September 22, 2025, 07:55:55 am
content: To fix bodges with magnet wire, I usually use this UV cured glue that is available in most hardware stores, at least in europe: UHU Led-light BoosterIt is viscous enough that will not flow everywhere, and you can lock it in place with the UV light, forming a solid that can be used also to fill and cover exposed parts.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 22, 2025, 08:13:08 am
content: If you have solid rosin (sometimes used instead of flux in TH soldering) cover the traces with a melted layer of rosin. Unless it is mechanically scratched away, the rosin will protect the traces forever.

author: Haenk
author_rank: Super Contributor
timestamp: September 22, 2025, 10:29:47 am
content: Quote from: RoGeorge on September 22, 2025, 08:13:08 amI'm pretty sure, this is neither moisture-proof not mechanically stable (might crack over time).The cheap solution is some nail varnish, I also like the UV cured stuff (reminds me of buying a set). However you don't know the electric properties of those - might be OK for power lines, might be a problem for analog signal lines.
Reselling oscilloscopes - Page 1
Forum section: electronics / repair

author: lern01
author_rank: Regular Contributor
timestamp: August 23, 2025, 07:09:03 am
content: I have a DPO3054 oscilloscope in very good condition and functioning normally, with a face mask, as shown below. If you're interested, please contact me. I also have several TDS3052B and 3054B oscilloscopes. They're all reasonably priced. Email:lern01@qq.com or lern01@outlook.com.

author: tggzzz
author_rank: Super Contributor
timestamp: August 23, 2025, 08:34:06 am
content: Since you have posted in the "repair" section, could you tell us how the scopes have been repaired or need repair. Otherwisehttps://www.eevblog.com/forum/buysellwanted/is the appropriate place.It is polite to state where you are located and where you will/won't send them, and the asking price.

author: Grandchuck
author_rank: Super Contributor
timestamp: August 23, 2025, 01:00:05 pm
content: Use the Buy/Sell/Wanted section.

author: lern01
author_rank: Regular Contributor
timestamp: August 25, 2025, 11:42:54 am
content: Thanks for the reminder, I'll remove it right away.

author: lern01
author_rank: Regular Contributor
timestamp: August 25, 2025, 11:49:46 am
content: Why can’t I delete it? After clicking Remove, return to the maintenance homepage and you can enter it again.

author: wraper
author_rank: Unknown
timestamp: August 25, 2025, 12:10:19 pm
content: Quote from: lern01 on August 25, 2025, 11:49:46 amYou can't do it once there are replies. You can ask a moderator to move it to another section.
Resin dipped axial capacitor identification - Page 1
Forum section: electronics / repair

author: Snake____1
author_rank: Contributor
timestamp: June 06, 2019, 03:29:02 pm
content: Hi everyone,I have a board in for repair, it's an old style with all through-hole components. I am used to SMD work so the markings on the capacitors were Greek to me.Does anyone have a link for a deciphering table or know the value of the capacitors attached?

author: capt bullshot
author_rank: Super Contributor
timestamp: June 06, 2019, 04:38:09 pm
content: I'm slightly confused, but following the standard decoding rule this would be 74 * 10e-1 -> 7.4pFSo it't the 7.4pF that makes me doubt the result since this isn't a standard value.

author: PKTKS
author_rank: Super Contributor
timestamp: June 06, 2019, 05:07:18 pm
content: These form factors appears in devices intermediate from THT to SMTIN general they CAN BE ANYTHING: RESISTOR/INDUCTOR/CAPACITOR/MOV/NTCThe figure is not showing the silk screen which I GUESS IS "Cxx" somethingbut even being C the label is not very common and markings are very oddreally they are close to SMD fabs with AXIAL leads...VHS systems from 90xx use to have a lot of these... DIODOES/RESISTORS/CAPSMarkings are pretty much the same nightmare of SMD things...vast majority requires a considerable time to decipherPaul

author: Snake____1
author_rank: Contributor
timestamp: June 06, 2019, 08:06:58 pm
content: These have the C107 + C108 etc. markings on the silkscreen. I measured a couple others on the same board, they read out everything from 74nF to 88nF. So deffinatley scratching my head... Are they supposed to be 74nf according to markings?BTW, thanks for the inputs so far...

author: coromonadalix
author_rank: Super Contributor
timestamp: June 06, 2019, 09:04:48 pm
content: I would guess a tons of 0.1 uf, in thoses times they did put lots of them, around your blue 34 pins connector, they are decoupling caps.Do you have an lcr meter ?? capacitance meter ??

author: floobydust
author_rank: Super Contributor
timestamp: June 06, 2019, 09:29:04 pm
content: OMG Q17 was hit by a truck, why are you worried about those capacitors. I doubt they are your problem.They look like old AVX ceramic capacitors, I thought they have two rows of numbers series and value. Never seen them fail.Tantalum C76 would be worth checking.
Resistor Breakdown in FY6800 Signal Generator - Page 1
Forum section: electronics / repair

author: robot.golem
author_rank: Newbie
timestamp: August 30, 2021, 02:05:31 am
content: Hello:I am repairing my FY6800 signal generator, and discovered that one of the SMD 49R9 resistors resistors literally broke in half (see 1-st photo). On the second photo there's peculiar yellowish residue at the soldering point (photo 2). What have cause the resistor to break? -- It does not look like a thermal breakdown, or is it?Thanks!

author: pcwrangler
author_rank: Regular Contributor
timestamp: August 30, 2021, 02:16:25 am
content: Looks like a faulty resistor resulting in catastrophic failure. You can see the burns on top and it had to get hot enough to flow the solder at least partially. Interesting break though. Lucky it didn't crater your pcb.

author: bob91343
author_rank: Super Contributor
timestamp: August 30, 2021, 03:36:21 am
content: It appears that a strong signal was put into this device. Making a 50 Ohm resistor that hot probably took a Watt or more.

author: pcwrangler
author_rank: Regular Contributor
timestamp: August 30, 2021, 04:12:24 am
content: Were you testing a transceiver and accidently hit the PTT?

author: robot.golem
author_rank: Newbie
timestamp: August 31, 2021, 07:36:26 am
content: I think it's a 1/2 W resistor, 1206 type. I will try to replace it, but it remains to be seen if the op. amp's output circuit is not fried as well. It would greatly help to have schematics for the board, but I could not find it, not for this model.

author: robot.golem
author_rank: Newbie
timestamp: August 31, 2021, 07:39:04 am
content: What is a PTT? This is not a final stage of the amplifier. Could it be affected at all by what I connect to the instrument's outputs?

author: bob91343
author_rank: Super Contributor
timestamp: August 31, 2021, 11:28:36 pm
content: PTT means push to talk, the transmit switch on a transceiver. The query was whether a transceiver was being tested and the transmit switch inadvertently operated, thus frying the output section of the generator.I did that to my HP 8657B. Its protection circuit wasn't enough to protect it and I damaged two ICs. Fortunately they were cheap and easy to replace and now the generator is functional again.

author: bobbydazzler
author_rank: Regular Contributor
timestamp: September 02, 2021, 11:33:00 am
content: Looks like it got hot enough to melt it's own solder and soft explode in the middle, fingerprint of a massive overload.
Resistor identification - Page 1
Forum section: electronics / repair

author: cpposteve
author_rank: Regular Contributor
timestamp: November 21, 2021, 01:19:09 pm
content: Hi all. Trying to identify this resistor and having a hard time as it doesn’t follow conventional colour coding specs. Pic attached. It’s on the mains incoming on a pcb. I’m hazarding a guess at it being 7.5 ohms but if someone could clarify and explain the banding on this I would be great full.ThanksSteve

author: coromonadalix
author_rank: Super Contributor
timestamp: November 21, 2021, 02:41:31 pm
content: https://www.hobby-hour.com/electronics/resistorcalculator.phpwich gives 7.5 ohms at 5% tolerancenormally you calculate it as a 4 band colors resistor, the black is used as a temperature coefficient ??Just probe it with a meter to confirm its value and match the website deciphered colors

author: madires
author_rank: Super Contributor
timestamp: November 21, 2021, 02:46:15 pm
content: 7.5 Ohms should be correct. The black ring is most likely an indicator for a fusible resistor. There is no common rule for fusible resistors. Some have an additional ring and the ring color depends on the manufacturer (so far I've seen black, white and green).

author: isometrik
author_rank: Regular Contributor
timestamp: November 21, 2021, 03:01:31 pm
content: QuoteThe RF1 reference designator also seems to imply a "R"esitors "F"usible.

author: bob91343
author_rank: Super Contributor
timestamp: November 21, 2021, 06:20:13 pm
content: The background color says fusible. Those are usually a sort of rough light gray. I agree it is 7.5 Ohms.

author: gamalot
author_rank: Super Contributor
timestamp: November 21, 2021, 07:52:29 pm
content: Quote from: madires on November 21, 2021, 02:46:15 pmI have only seen black, white and green additional color rings, I am curious if there are any other colors.
Resistor metal film or metal oxide? - Page 1
Forum section: electronics / repair

author: Jwalling
author_rank: Unknown
timestamp: July 27, 2020, 11:45:54 am
content: R30 is open. It's .47 Ohms 5%Not sure if it is metal film or metal oxide. Does it even matter?Thanks!Not sure of the wattage either. it's body is 15mm in length.

author: Zero999
author_rank: Super Contributor
timestamp: July 27, 2020, 05:07:30 pm
content: It looks like a metal oxide resistor.It's quite likely something else caused it to fail, in which case replacing it would only result in another dead resistor.What does the circuit do?

author: KevinA
author_rank: Regular Contributor
timestamp: July 27, 2020, 05:15:36 pm
content: Looks decidedly US audio amplifier; what model is it?

author: 2N3055
author_rank: Super Contributor
timestamp: July 27, 2020, 05:44:09 pm
content: That looks like current sharing resistor for those transistors in parallel.. Both metal film or metal oxide power resistor should be fine, 2-3W by the looks of it. And like Zero999 said, that happened if transistor was hogging current. I would check it too..

author: Jwalling
author_rank: Unknown
timestamp: July 29, 2020, 10:49:31 am
content: Quote from: 2N3055 on July 27, 2020, 05:44:09 pmThanks. I checked all the transistors and they're all fine. This is a voltage amplifier board for a Arbiter Systems panel meter calibrator. No schematics as is usual for this type of equipment. It fails it's power on voltage mode self test. I've ordered 3 replacement 3W metal oxide resistors. If the first one blows, then I'll have to look a bit deeper into the failure...

author: 2N3055
author_rank: Super Contributor
timestamp: July 29, 2020, 11:09:04 am
content: Quote from: Jwalling on July 29, 2020, 10:49:31 amGlad if it was any help.Sometimes resistors can degrade from heat and than they simply oxidize to death...So it might be OK. I'm glad you ordered all 3, I forgot to mention that, if they are current sharing, you want them to be the same tempco if nothing else, and the remaining 2 might have degraded too.. But you obviously knew thatRegards,Sinisa
Resistor Test problems Fluke 75 Series II - Page 1
Forum section: electronics / repair

author: kdl1950
author_rank: Contributor
timestamp: July 12, 2024, 05:50:28 pm
content: Hello everyone, I have a problem again.This time with a Fluke 75.The error lies in the fact that a value of 0.00 ohms is not possible when measuring the resistance.If the input is short-circuited, the measuring device starts at approx. 20 ohms and runs to a final value of 1.2 ohms in approx. 1 minute. (see pictures).I have already tested internally without the connection socket. Same error pattern.Thus the bushings can be excluded. The cable is new and tested on other measuring devices. It looks like a capacitor is changing?!?!Does anyone have an idea or knows the problem? I checked the various internal resistances. All OK.What is also noticeable is a similar problem with the diode/continuity test.It takes a certain amount of time until the value approaches 0.00.It won't be quite 0 either.Continuity testing works immediately and has no problems.Greets from Germany

author: m k
author_rank: Super Contributor
timestamp: July 16, 2024, 04:11:24 pm
content: Manual has Schematics.Get hair dryer and non conducting cold spray can.Warm up the thing with a hair dryer.If lower resistance value appears sooner than without the dryer move to the next step.Learn to shoot cold spray so little that only a single drop comes out.Put that drop on the suspicious component.You can also drop it on a single pin.With luck you find a source that is external.It can also be a dirty selection wheel.

author: steerage250
author_rank: Newbie
timestamp: August 02, 2024, 08:58:35 am
content: Any luck solving this? (I have the same problem - and I don't want to through-away my faithful old Fluke!)I found a service manual for it on the Fluke website, but the schematic and component layout differ from my circuit board (the differences start immediately at the V/ohms input terminal where the schematic shows it connecting to 2 resistors, whereas mine connects to one resistor and the spark gap device)

author: kdl1950
author_rank: Contributor
timestamp: August 02, 2024, 06:17:21 pm
content: Hello steerage250,yes, there are insights and I can make it relatively short.I found the crucial clue here: "Fluke 77 III Resistance measurement fault"U1 has a defect or breaks.I heated the chip properly for a short time using a hot air dryer.The result is or was that the resistance measurement immediately goes back to 0.00 ohms. Unfortunately the measurement drifts away again after a few days.You can try it.The problem is definitely with the chip U1.I just reheated the chip. Here the result. From 0.02 to 0.00 in about 5 seconds.It remains to be seen how long the “repair” will last.At some point even a solid multimeter will reach the end of its life.

author: squadchannel
author_rank: Frequent Contributor
timestamp: August 03, 2024, 01:07:36 am
content: Is it any chance that the solder has cracks in it?If it does not work after re-soldering, then give up
resistor value - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: October 28, 2019, 10:35:39 am
content: hi all,ive a flourescent tube driver board thats faulty,there is a resistor open on it,its marked funny,going from right to left the bands are as follows green black silver gold,im not sure what the silver band is for,any ideas?

author: madires
author_rank: Super Contributor
timestamp: October 28, 2019, 11:19:32 am
content: It's the multiplier, in this case 0.01. Gold would be 0.1.

author: m3vuv
author_rank: Super Contributor
timestamp: October 28, 2019, 11:36:01 am
content: I think ive sorted it with the help of google,it would seem its a 0.5 ohm resistor,on the pcb on the silkscreen it is marked FU,with what looks like a strait line between the holes where it fits,so could it b3 a .5ohm resistor used as a fuse?

author: madires
author_rank: Super Contributor
timestamp: October 28, 2019, 02:07:14 pm
content: Yep, could be a fusible resistor.
(solved)Resistor value for buzzer. 12V 2sc9013 transistor - Page 1
Forum section: electronics / repair

author: georgian
author_rank: Regular Contributor
timestamp: October 13, 2025, 05:43:01 pm
content: Hello, I have here an small PCB with an buzzer and one resistor is missing.Buzzer signal goes to an 5k2 resitor and transistor base. Emiter is connected to GND, Collectrt to one buzzer pin. Other buzzer pin is on 12V. There used to be an resistor parallel to the buzzer and is missing.... Just a sanity check. 100kOhm here should be no problem, right?

author: coromonadalix
author_rank: Super Contributor
timestamp: October 13, 2025, 05:48:00 pm
content: around 1k to try ?

author: georgian
author_rank: Regular Contributor
timestamp: October 13, 2025, 05:49:55 pm
content: Thanks. I only have the PCB here. I'll hook an arduino to test it. My guess is that parallel resistor will decrease/increase the laudness, right?

author: georgian
author_rank: Regular Contributor
timestamp: October 13, 2025, 06:41:27 pm
content: Quote from: coromonadalix on October 13, 2025, 05:48:00 pm1k worked fine. 10k same laudness. I put an 10k in and call it done.
Resistor values in Rigol 2072A front end - now with picture... - Page 1
Forum section: electronics / repair

author: ss
author_rank: Newbie
timestamp: August 14, 2023, 12:09:00 am
content: Anyone have the correct resistor values of the Rigol DS2072A front end.Accidently applied an overvoltage to the channel and it damaged the front end.When I compare the resistor values with a working channel, it looks like I blew out:1x 2512 49.9R1x 0603 62R1x 0603 82R1x 0603 68R(see attached picture - green=good channel, red=where bad channel was different.Does anyone know the correct values of these resistors?They are all unmarked and without knowing the circuit it is hard to know if anything else is affecting my measurements.

author: ss
author_rank: Newbie
timestamp: August 14, 2023, 04:23:16 pm
content: That is perfect.I googled my way to that info yesterday, but it had be entered into a wordpress site and the resolution on the schematic was so poor I could not tell capacitors from resistors and it wasn't even obvious the schematics had values.