hybridfree/eevblog-posts huggingface dataset:
Diode ID - Page 1
Forum section: electronics / repair

author: Chemist_Guy
author_rank: Newbie
timestamp: October 12, 2023, 06:26:40 pm
content: I have a Cal Controls #3300 (Code: 330000005). As you can see from the pictures, it's kind of obvious which part has released the magic smoke.It's a diode and it has the code85C150GPI'm pretty sure I know what it is, but I'd like a second opinion before I do something stupid. Thanks

author: fzabkar
author_rank: Super Contributor
timestamp: October 12, 2023, 06:41:53 pm
content: 85V unidirectional TVS diode?
Resistor identification - Page 1
Forum section: electronics / repair

author: Hickbilly
author_rank: Newbie
timestamp: September 20, 2023, 10:27:53 pm
content: I have inadvertently burned up two resistors on my Amprobe-Am2. They appear to be on the Rx1 and Rx10 positions. I need help identifying these. Any help appreciated. Thanks in advance.

author: TimFox
author_rank: Super Contributor
timestamp: September 20, 2023, 10:28:55 pm
content: The two burned-out parts appear to be resistors, not diodes.

author: Hickbilly
author_rank: Newbie
timestamp: September 21, 2023, 04:21:55 pm
content: You are correct.

author: MF-jockey
author_rank: Regular Contributor
timestamp: September 21, 2023, 05:06:01 pm
content: The topic should contain "Amprobe-Am2", then there might be a user with such a device who can help.

author: floobydust
author_rank: Super Contributor
timestamp: September 21, 2023, 08:15:20 pm
content: I couldn't find a schematic for the Amprobe AM-2, it seems to not be in the manual? Released in 1975.With that kind of overload, I would also check the diodes and meter coil survived.Found an old eBay listing pic that give one part's value. The small resistor appears to be 967Ω and the larger starts with a "9" and as a decade smaller it must be in the 90's and surely a popular smoker for Rx1 range. I doubt you'd find either today using EIA values and have to parallel two.You could take a picture of the other side of the PC board and sketch a schematic of the multimeter, to better figure it out.

author: TimFox
author_rank: Super Contributor
timestamp: September 21, 2023, 08:28:12 pm
content: Quote from: MF-jockey on September 21, 2023, 05:06:01 pmA suggestion for new posters:If you start your thread title with "Amprobe-AM2", it will show in the shortened title listed in the index and possibly attract useful replies.

author: floobydust
author_rank: Super Contributor
timestamp: September 21, 2023, 08:49:49 pm
content: OP is new, it's alright- they can find out how to edit a thread title to make it more successful.I did see Amprobe AM-1, AM-2 and AM-2E etc. many different models in search results. Not sure if a dash is considered whitespace.
DIODE N46 - Page 1
Forum section: electronics / repair

author: lionelkjh
author_rank: Frequent Contributor
timestamp: April 09, 2021, 02:31:22 pm
content: Good morning all!; I am still asking you for the identification of a component. This time, it's a diode (box: SOT), with the marking: N46. What exact model can it correspond to? Thank you for your help (no photo possible, because the shot is blurry .....) Cdt

author: seebeck
author_rank: Contributor
timestamp: April 10, 2021, 01:35:00 am
content: Hi lionelkjh,Top marking "N46" under SOT-23 package is AZ431LANTR, it is a low voltage adjustable precision shunt regulator.
Diode replacement - Page 1
Forum section: electronics / repair

author: Ropterex
author_rank: Newbie
timestamp: March 16, 2020, 03:22:53 pm
content: Hi! yesterday I had mi PC's power supply blow up on me, upon some inspection I found a broken diode inside (stpsc606d). Its the first time im trying to fix something like this, so I have a few questions maybe someone can help me with:1. the power supply is about 6 years old, could it be that de diode blew up on its own? or is this just a sign of a deeper issue. Could it have been a power surge? (I didnt have any surge protection at the time)2. Im from Argentina, so I can't finde this exact sane diode to replace it, is it posible to use something "more common" that I can actually buy here?Thank you for your help! sorry for the bad english.

author: TheMG
author_rank: Frequent Contributor
timestamp: March 17, 2020, 12:57:41 am
content: That's a relatively low current but high voltage schottky diode, so I'm assuming it must be part of the PFC pre-regulator circuit?If so, then it is highly likely there is a lot more wrong than just the diode. They do not usually blow apart like that for no reason, something else is probably shorted (likely the main switching transistors of the power supply) that caused grossly excessive current to flow through it.

author: bob91343
author_rank: Super Contributor
timestamp: March 17, 2020, 03:46:20 am
content: Good answer, but my first guess is that the diode is rellatively cheap. So I would take a chance and replace it to see if things start to work.

author: james_s
author_rank: Super Contributor
timestamp: March 17, 2020, 04:32:21 am
content: At the very least test the chopper transistor and any other semiconductors in the area. There's no point in wasting time replacing the diode only to have it blow up again from other parts being bad. 99.9% chance there are other faults.

author: Ropterex
author_rank: Newbie
timestamp: March 18, 2020, 02:10:00 am
content: Thank you for taking the time to answer!
Diode replacement for non-available Motorola MR501 - what to look for? - Page 1
Forum section: electronics / repair

author: nightfire
author_rank: Frequent Contributor
timestamp: May 14, 2022, 12:10:14 am
content: In a linear power supply (without schematics) I am currently repairing (and learning valuable stuff) I identified a probably faulty diode, that has shortened.As the Model (Motorola MR501) is not available anymore, I would have to look for a good quality replacement.As the general question how to look for replacement for ancient standard parts probably is of use for other people, I put it in as a separate thread and not under the repair thread for the Power Supply (https://www.eevblog.com/forum/repair/hdl-research-lab-military-power-supply-lcd-replacement)@mods: If not ok, could you merge it then?I would ask for some advice on how to select a replacement diode for this application.From what I already looked up in the datasheets are the obvious things like same case, rated voltage, similar reverse/forward voltages and not to forget the heat dissipation in dependency of the mounting conditions.But: What about the frequency response, resp. behaviour under load? In this regard, I would appreciate any tips from practical experience.FRom the datasheethttps://www.datasheets360.com/part/detail/mr501/-5038348702330472923/I see the following values:Motorola MR501Standard Recovery Power Rectifiers50-1000 Volts3 AmpsCase 267-01Peak Repetetive Reverse Voltage/DC Blocking Voltage(VRRM/VRWM/VR): 100Non-Repetetive Peak Reverse Voltage (VRSM): 150Average Rectified Forward Current (IO): 3 AmpInstantaneous Forward Voltage (VF): Typ 0.9, Max 1.0 VoltReverse Current (IR) Typ. (25 Deg C) 0.1, Max 5.0 µA100 deg C Typ. 2.8, max 25 µADimensions: 5 mm diameter, length 9,5 mmFrom what I have seen, I concluded that some standard 1N5408 diode could be a possible replacement? But those (at least the Onsemi 1N5408RLG my favorite shop is carrying) have some higher max. reverse current of 10 µA instead of 5µA of the Motorola version.What negative effects could this yield?

author: fzabkar
author_rank: Super Contributor
timestamp: May 14, 2022, 12:18:27 am
content: https://www.vishay.com/docs/88516/1n5400.pdf1N5408 would have been my choice, too.I wouldn't be concerned about the difference in reverse current in your application.
Diode SMD XT marking - Page 1
Forum section: electronics / repair

author: TobiasG
author_rank: Contributor
timestamp: September 05, 2024, 11:39:08 pm
content: Could you help me to find this diode Datasheet?

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2024, 12:35:27 am
content: SMAJ18CA bidirectional 18V TVS diode

author: TobiasG
author_rank: Contributor
timestamp: September 06, 2024, 11:47:32 am
content: Do you know the manufacturer?I can't recognize this logo

author: VinzC
author_rank: Frequent Contributor
timestamp: September 06, 2024, 12:38:56 pm
content: Quote from: TobiasG on September 06, 2024, 11:47:32 amIf you perform a web search onSMAJ18CAyou will know...

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2024, 05:04:21 pm
content: Quote from: TobiasG on September 06, 2024, 11:47:32 amVishay / General Semiconductorhttps://www.vishay.com/docs/88390/smaj50a.pdf
Diode substitution advice - class D gate driver - Page 1
Forum section: electronics / repair

author: darkflow
author_rank: Newbie
timestamp: July 10, 2023, 10:59:16 pm
content: I'm hoping for some advice with strategy for replacing an open circuit diode in the gate drive circuit for a Yamaha subwoofer class D amplifier.The failed diode is D118 (indicated by a red arrow, on the right) in the attached schematic. Being open, there is no turn off path for Q110, various protection mechanisms cut in, and the thing can't run.The MA2J111 is a fast recovery, low capacitance diode: 80V, 100 mA / 225 mA, 3ns, 0.6 pF. It's obsolete, and I'm struggling to find an equivalent.What I'm thinking of doing is relocating D139 (indicated by red arrow, on the left) to replace D118 and just using a 1N4148: 100V, 200 mA, 4ns, 4 pF to replace D139.The rationale is to keep the output stage symmetrical and hope that a slightly slower / higher capacitance diode in the D139 position will be OK, as it's in a digital signal path.I'd really appreciate any advice, thanks.

author: thm_w
author_rank: Super Contributor
timestamp: July 12, 2023, 09:38:41 pm
content: BAS516, BAS16L, or BAS316 would probably work as equivalents.But I like your idea of stealing the diode from another area of the circuit, I'm sure that would get it up and running faster. They clearly just used MA2J111's in multiple places where they needed a generic diode.

author: darkflow
author_rank: Newbie
timestamp: July 13, 2023, 10:00:46 pm
content: Many thanks for the diode recommendations.I went ahead and did as I planned, and it seems to have worked out OK - powers up, no protection cut out, DC offset voltage at the speaker terminals within spec.The only problem now is that my previous quick continuity check on the 4 ohm voice coil missed the fact that it is actuallywayless than 4 ohms, and a different protection mechanism now cuts in if the speaker is connected. This thing has been through some adventures before coming into my hands and there is evidence of past repairs on the amplifier PCB, so I assume the voice coil is fried.Ah well - time to replace the expensive driver with an affordable one, or to learn how to re-voice coil a speaker ...
Diode test result odd? - Page 1
Forum section: electronics / repair

author: ControlsLost
author_rank: Contributor
timestamp: March 07, 2022, 03:35:23 am
content: During a standard diode check to determine the health of some 3 phase Bridge rectifiers and output IGBT module on a 590amp/500hp (cabinet size) VFD. I encountered what i though was probably normal, but odd because I hadn't seen it before.Diode check in forward bias was normal, 560mv across the board on the Line side to dc bus, then 225mv on the load side IGBT to dc bus.But when checking the reverse bias for a short. I would see the voltage slowly (took about a minute) rise to the meters maximum of around 3 something volts before going OL like it's supposed to when they are good and not conducting through. and when I would remove the lead for a few seconds then put it back on, it would start at about 3 something volts and climb again to OL.So it's obviously increasing in the voltage drop slowly before finally giving me a reading with no voltage drop.I believe it's got something to do with the sheer size of the unit, the diodes in this to run a 500hp 3 phase motor would have to be hefty.What am I seeing here where the diode voltage drop increases slowly and seems like its varying in resistance when the meter gets connected/disconnected, like its slowly charging and discharging?Testing done with a fluke 87v.Thanks!

author: bob91343
author_rank: Super Contributor
timestamp: March 07, 2022, 07:03:09 am
content: Being tested in the circuit gives strange results. What you are seeing may be the filter capacitor charging.

author: m3vuv
author_rank: Super Contributor
timestamp: March 07, 2022, 12:51:32 pm
content: I would say the same as bob as in its charging a cap,pull one leg and retest.

author: ControlsLost
author_rank: Contributor
timestamp: March 07, 2022, 07:58:00 pm
content: Quote from: bob91343 on March 07, 2022, 07:03:09 amappreciate the advice.Unfortunately the way these are, thats an hours long process to remove the power modules and possibly remove capacitors. These are designed to be able to test in circuit. Like you said though, there is some charging going on, I just wasn't sure how much to expect.I actually found a good answer in a separate manual for a newer version of these drives. It calls it out explicitly that there will be some charging due to capacitors and such.troubleshooting visual / 0Drive in question (this unit is about 7 feet tall)Found the answer here. So that explains it, appreciate it guys
Diode / Transorb Identifcation - Page 1
Forum section: electronics / repair

author: andybarrett1
author_rank: Regular Contributor
timestamp: October 11, 2024, 03:40:44 pm
content: HiThank you for reading ..... Attempting to find out what this might beI suspect a Zorb / Transorb but dont know for sureAnyone help ?Thank YouAndy

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: October 11, 2024, 11:33:20 pm
content: Looks more like a 33uF/16V tantalum or SMD electrolytic to me. Can it be measured out of circuit?

author: fzabkar
author_rank: Super Contributor
timestamp: October 12, 2024, 12:07:40 am
content: https://produto.mercadolivre.com.br/MLB-2202315714-kit-09-capacitor-smd-33uf-16v-nec-_JMhttps://http2.mlstatic.com/D_NQ_NP_2X_924798-MLB49336248347_032022-F.webp(photo)

author: andybarrett1
author_rank: Regular Contributor
timestamp: October 12, 2024, 09:16:54 am
content: I think you are right ....Thank youIt has gone dead short so can't measureThank you for helpAndy

author: andybarrett1
author_rank: Regular Contributor
timestamp: October 12, 2024, 09:19:00 am
content: It is thisThank you 🙏
DIP8 power supply IC, unknown  - Page 1
Forum section: electronics / repair

author: najrao
author_rank: Regular Contributor
timestamp: November 27, 2024, 09:40:17 am
content: Has no markings at all, this switcher converts 300V dc to 5V 6A, claimed. Comparable to Power Integrations devices.The traced pinout is:1: GND, 300V Minus2: Unknown, has 220R to Vcc cap Plus3: Vcc, 10uF cap fed by a transformer sec, with 2×500k to 300V for startup4: FB, from Opto LED5: Source of switch, has 560mR 0.5W to power ground6, 7 and 8: Drain, to transformer primary.All 8 pins present, none deleted to extend hv drain clearance.Problem is: it is kaput,SHORTbetween 2 and 3. Vcc builds up to 17.5V nevertheless. No switching action though. Power mosfet tests OK, source to drain..Claim of 30W output with not much heatsinking estate on PCB is suspect.My Google and other searches have failed. Anybody can identify this IC?Thanks in advance.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 27, 2024, 02:59:47 pm
content: photos of it could help, pcb markings etc ...

author: fzabkar
author_rank: Super Contributor
timestamp: November 27, 2024, 08:03:18 pm
content: Try this resource:https://remont-aud.net/ic_power/

author: Kim Christensen
author_rank: Super Contributor
timestamp: November 27, 2024, 08:38:44 pm
content: Quote from: najrao on November 27, 2024, 09:40:17 amHave you checked the ESR of that 10uF? When they go high ESR, the chip cannot bootstrap itself and will appear to be faulty when it's really the capacitor.

author: najrao
author_rank: Regular Contributor
timestamp: November 28, 2024, 03:43:00 am
content: Photo/s show nothing more.I have already said Vcc cap starts up, reaches 17.5Vwithoutbeing fed by transformer. ESR check has no value.Excellent 'resource' to ID by pinout but alas, no match in list. Thank you sir.

author: fzabkar
author_rank: Super Contributor
timestamp: November 28, 2024, 04:01:15 am
content: Quote from: najrao on November 28, 2024, 03:43:00 amThis would suggest that Vcc is clamped by an internal zener, unless the capacitor is leaking.
Direct current overflow issue in Keithley DMM 6500 digital multimeter - Page 1
Forum section: electronics / repair

author: fracton
author_rank: Contributor
timestamp: September 30, 2024, 05:58:47 pm
content: Hi there!I am facing overflow issues in direct measurements (DCI) with Keithley's DMM6500. This 6.5 digit, digital multimeter claims to be able to measure currents from 10pA to 10 A. While this was working well for sometime, I have run into overflow issues for currents upto 3A range on both the front and rear panels. However, I am able to measure the current on the 10A pin. I am guessing there's some issue with the autorange function or the current digitization as the autorange does not work for the 10 A range (for reference see the attached image).Also, I've checked the fuses on both front and rear panels, both seem to be fine. Has anyone face similar issues? Would it help to reset/update the firmware?I am not sure if its hardware issue, going by the layout explained in this teardown by Signal Path
Dirt, corrosion, flux and other random stuff cleaning  - Page 1
Forum section: electronics / repair

author: ianscott
author_rank: Contributor
timestamp: October 20, 2020, 12:56:56 am
content: Hey AllJust before I run out to buy an ultrasonic cleaner, what do you guys think is the best way of cleaning this attached board? Its a combination of dirt/dust, corrosion, flux, oil and other random stuff the fan next to it has brought in.Thanks!

author: Haenk
author_rank: Super Contributor
timestamp: October 20, 2020, 08:52:47 am
content: Very much depends on the components.The flux stuff can be removed with IPA.That battery corrosion can be removed with hot water and soap, maybe add a bit of vinegar. Wash with destilled water and put some laquer on the bare traces. *But* this very much depends on the parts on the other side and if it might leak through.

author: m k
author_rank: Super Contributor
timestamp: October 20, 2020, 09:53:59 am
content: Make a tight tuft from a kitchen paper tower.Spray the area with todays freon and start brushing.Finally clean shredded and dirty paper bits.
Disable wireless charging on Chinese power bank! - Page 1
Forum section: electronics / repair

author: rks96
author_rank: Contributor
timestamp: May 30, 2023, 05:41:08 pm
content: I bought a cheap Chinese DIY powerbank because it advertised the VOOC charging protocol. Tested, and it indeed fastcharges! The Powerbank also supports wireless charging. However, the power bank shell doesn't close properly if the wireless coil is fitted in its designated place. For now, I have simply removed the coil and capacitor between the H bridge and battery power, but the power bank randomly signals that it is trying to charge. Everything else works fine without coils and capacitor. Powerbank uses IP5568 ichttp://www.injoinic.com/wwwroot/uploads/files/20200214/7d8b85b3d51f5d9bd44f292fb1bf5e9a.pdf. I have searched in the datasheet for a use case without wireless charging, but such a use case isn't offered. My question is: is it ok to leave it as it is, or maybe someone else knows a better and more appropriate solution for disabling wireless charging?

author: rks96
author_rank: Contributor
timestamp: May 30, 2023, 06:39:09 pm
content: I should add that the power bank signals about wireless charging only when it is charged or it is charging something! While the power bank is in standby (off), everything is fine.

author: m k
author_rank: Super Contributor
timestamp: June 07, 2023, 07:35:58 pm
content: Their naming of 7-segment display module is not very promising.Since you've removed the power exchange part it's not moving very much power, so hardly much other effects either.Some signals can be floating and misinforming, but I wouldn't be very nervous.Anyway, I would still try to reposition that coil few times.
Disassembly and Reapir DeLonghi  ENV120W  - Page 1
Forum section: electronics / repair

author: geshka
author_rank: Regular Contributor
timestamp: May 10, 2022, 02:14:46 pm
content: Hello team.My DeLonghi ENV120W coffee maker is not turning on anymore. Tried to disassembling but has no luck removing back plastic cover. Bottom part is unscrewed but not coming off either. Any ideas of how to take it apart without breaking would be appreciated.

author: m k
author_rank: Super Contributor
timestamp: May 18, 2022, 03:19:39 pm
content: Still intact?Maybe it's just stuffed together with some hidden clips.

author: fzabkar
author_rank: Super Contributor
timestamp: May 18, 2022, 05:32:40 pm
content: Perhaps you might find the instructions in the service manual for a similar model?https://elektrotanya.com/showresult?what=DeLonghi+&kategoria=All&kat2=All
Dishwasher GE GSC3500D35WW Electric Diagram - Page 1
Forum section: electronics / repair

author: Miti
author_rank: Super Contributor
timestamp: December 03, 2023, 01:43:34 am
content: I have an old dishwasher GE model GSC3500D35WW that I need the electric diagram for. Does anyone have it? Yes, I've tied Google, can't find it.Cheers,Miti

author: fzabkar
author_rank: Super Contributor
timestamp: December 03, 2023, 06:13:59 am
content: I only managed to find a spare parts list and drawings:https://visualizador.serviplus.com.mx/datos_pt/glob/manuales/GSC3500D35WW.pdf

author: jpanhalt
author_rank: Super Contributor
timestamp: December 03, 2023, 11:11:44 am
content: Last Spring, I repaired my Maytag dishwasher that has been non-operative for about 6 months. You will probably not fins a detailed electrical diagram. Service is at the module level only.For such appliances in the US, a high-level design and limited trouble shooting guide is folded and placed behind some service panel. I found the trouble shooting of limited help. It did not identify the problem, but it did help me identify flaky tactile buttons on the control panel, which had to be replaced as a unit.
Display cable connector in BK Precision function generator - Page 1
Forum section: electronics / repair

author: David1
author_rank: Contributor
timestamp: February 11, 2021, 08:52:29 am
content: Hi,Do you know how to disconnect the 20-cable display connector in the attached images please?It's in a 1996 BK Precision 4017A function generator. The other connectors in this piece of equipment have interlocking plastic retaining tabs but this one is different.ThanksDavid

author: David1
author_rank: Contributor
timestamp: February 12, 2021, 06:58:26 am
content: There are two little lugs that trap a ledge at the bottom of the plug. This is completely hidden when plugged in.Gentle leverage with a thin-bladed screwdriver worked but did cause some damage (nothing serious). But I'll do it differently next time!

author: m k
author_rank: Super Contributor
timestamp: February 13, 2021, 02:23:14 pm
content: Heh,have I missed those lugs through the decades.Obviously I've just pulled them out, partially from the cable and off you go stylish.Some recollections I have that they were not very loosely but nothing about those lugs.Though my case was a bit different.It's a mass production and female part is own, but I still don't believe any tool was meant to be involved.

author: tooki
author_rank: Super Contributor
timestamp: February 13, 2021, 04:07:03 pm
content: That’s a Molex KK 254, TE MTA 100, or one of the countless clones thereof. You just grab the connector body and pull. Wiggle if necessary.
DISPLAY FLUKE 287 CON BAJA VISUALIZACIÓN - Page 1
Forum section: electronics / repair

author: Genaro Moscol Saavedra
author_rank: Newbie
timestamp: July 22, 2020, 05:42:04 pm
content: Hola estimados, en la empresa para la cual trabajo hicieron la compra de varios multimetros FLUKE 287, despues de 01 año los traen para calibración y resulta que llegaron 03 con el display atenuado su visualización era muy baja. Así mismo retire uno de los display supuestamente averiado y lo coloque en uno que está en buenas condiciones y la sorpresa es que el supuesto display averiado esta bueno. Luego instale el display del multímetro bueno al multímetro con falla y sigue presentando la misma falla de display con baja visualización, con esta prueba queda descartada que la falla sea el displayLes consulto si alguien tuvo una falla similar o que debo hacer para poder repararlos.Queda descartada la garantía extendida de FLUKE porque fueron comprados a un tercero.Espero sus respuestas.

author: Genaro Moscol Saavedra
author_rank: Newbie
timestamp: July 22, 2020, 05:45:03 pm
content: Muestra de los display.

author: dacman
author_rank: Frequent Contributor
timestamp: July 22, 2020, 09:10:42 pm
content: There is a Contrast setting somewhere in the Setup section. (I'll try to translate this using Google.)Hay una configuración de Contraste en algún lugar de la sección Configuración.

author: dacman
author_rank: Frequent Contributor
timestamp: July 22, 2020, 09:12:57 pm
content: One of the screens looks like it still has the protective cover on it and might be clouding up.Parece que una de las pantallas todavía tiene la cubierta protectora y podría estar nublándose.

author: Genaro Moscol Saavedra
author_rank: Newbie
timestamp: July 23, 2020, 04:46:54 pm
content: Gracias estimado, no me percate de esa opción.Un abrazo a la distancia.
Display for the Fluke 75-III - Page 1
Forum section: electronics / repair

author: edisitaru
author_rank: Contributor
timestamp: April 25, 2023, 07:46:04 pm
content: HelloI need to buy a display for the Fluke 75-III, part number Fluke 602927. Can it still be found somewhere or can it be replaced with another type of Fluke display?Thank you in advance!!

author: Paceguy
author_rank: Regular Contributor
timestamp: April 26, 2023, 07:33:34 pm
content: Look on ebay, there are many Fluke LCD displays listed there.

author: Axtman
author_rank: Regular Contributor
timestamp: April 27, 2023, 04:21:48 am
content: What is wrong with your display? Pictures please.

author: edisitaru
author_rank: Contributor
timestamp: April 27, 2023, 08:06:06 pm
content: Is broken....

author: edisitaru
author_rank: Contributor
timestamp: June 25, 2023, 05:46:41 pm
content: It works perfectly!!https://www.ebay.com/itm/385132782544
Display issue Lab Power Suply 3005d Velleman/Korad - Page 1
Forum section: electronics / repair

author: Neutron72
author_rank: Newbie
timestamp: January 24, 2021, 06:15:29 pm
content: What might have happened to the display on my Velleman (Korad) Labps3005d. I had to change a faulty rotary encoder and after a misshapen with the reassembling, one row of the pins of the connector J6 on the main board ended up connecting the wrong row on the connector of the key board. Not noticing this I powered up the power supply and ended up with the display issues shown in the attached pictures. The different patterns, on the voltage and current display, turns up different every time I power the unit on and off. Pressing any of the buttons most likely have an effect according to the multimeter measuring the output. With the output turned on I can see the the voltage being changed accordingly, on the multimeter. So the values measured inside the power supply works but it doesn't show up on the display. Maybe it's not worth the money to fix it, but the experience of troubleshooting the problem might be worth some time spent.Any thoughts and ideas?

author: tooki
author_rank: Super Contributor
timestamp: January 24, 2021, 07:14:24 pm
content: Most of the schematics can be found here:https://elektrotanya.com/korad_ka3005p_velleman_labps3005d_power_supply.zip/download.htmlAnd here:https://www.eevblog.com/forum/repair/korad-ka3005p-power-supply-calibration/msg370823/#msg370823https://github.com/djedditt/ka3005p-displayLooks like the displays are bit-banged via plain old 74HC595 shift registers, so that’d be a good place to start. (The schematic in the zip showing the display driver as a 74HC95 has to be a typo, because it matches the 595, while the 95 is a 4-bit shift register, which simply doesn’t match the schematic and doesn’t even have the same number of pins.)

author: Neutron72
author_rank: Newbie
timestamp: January 30, 2021, 01:09:49 pm
content: After some gathering of equipment and spare parts, and then some beginners mistake of riping off traces and pads, desoldering the damaged shift registers, and then repairing traces and pads, I managed to attach two new 74HC595D shift registers. And guess what, IT WORKS A TREAT!!!Thanks a bunch "tooki" for the pin point tip of what might have been the problem.
Display problems with TDS3014B - Page 1
Forum section: electronics / repair

author: perdrix
author_rank: Frequent Contributor
timestamp: February 28, 2020, 10:15:17 am
content: Just bought this on eBay. The vendor states:QuoteWhile I'm waiting for it to arrive I thought I'd ask here if anyone has encountered this problem before and what the solution was.ThanksDavid

author: JFJ
author_rank: Regular Contributor
timestamp: February 28, 2020, 02:37:24 pm
content: This thread may help:https://www.eevblog.com/forum/repair/tektronix-tds3034b-display-failure/

author: perdrix
author_rank: Frequent Contributor
timestamp: March 04, 2020, 08:40:17 am
content: The good news is that it arrived and the display had the odd glitch or two, but opening the beastie (what fun that is), and removing/reseating the connector from the main board to the display (and every other connector in sight), plus clearing out the dust seems to have fixed it (fingers crossed). I tried to up-hack to TDS3064B after upgrading firmware to 3.39 but didn’t work using Keysight VISA utility . Couldn’t get TekVisa to play A 9 pin null modem cable just arrived and I connected to the scope using Putty (9600,N,1 RTS/CTS) with local echo turned on:*IDN?TEKTRONIX,TDS 3014B,0,CF:91.1CT FV:v3.39 TDS3GV:v1.00 TDS3LIM:v1.00 TDS3FFT:v1.00 TDS3TRG:v1.00password pitbullmconfig tds3064bPowered off, and then:*IDN?TEKTRONIX,TDS 3064B,0,CF:91.1CT FV:v3.39 TDS3GV:v1.00 TDS3LIM:v1.00 TDS3FFT:v1.00 TDS3TRG:v1.00Checking with an SG504 shows the 3db point into 50 ohms (1Vpp in displayed .707V) is at 760MHz.D.
Display Repair Honda CBR 600 RR 2003 - Page 1
Forum section: electronics / repair

author: reaper04
author_rank: Newbie
timestamp: July 13, 2023, 01:03:57 pm
content: HelloIm riding a Honda CBR 600 RR 2003, recently i discovered that both of my buttons on the display arent working at all. When I press them theres no resistance. The Display itself is working fine, i dont wanna swap the whole display because that would cost to much. Whats the best way to find out which parts are broken, and how do I replace them

author: LA7SJA
author_rank: Regular Contributor
timestamp: July 13, 2023, 02:09:13 pm
content: You could try to watch this:Johan-Fredrik

author: reaper04
author_rank: Newbie
timestamp: July 13, 2023, 02:26:14 pm
content: Thanks i will try that

author: LA7SJA
author_rank: Regular Contributor
timestamp: July 19, 2023, 08:57:09 am
content: Now, have you tried?Johan-Fredrik

author: reaper04
author_rank: Newbie
timestamp: July 19, 2023, 10:02:41 am
content: Im still waiting for my switches to arrive

author: LA7SJA
author_rank: Regular Contributor
timestamp: October 03, 2023, 12:26:02 pm
content: Godot?
Display shows black screen  - Page 1
Forum section: electronics / repair

author: funky2x
author_rank: Contributor
timestamp: July 21, 2025, 07:07:05 am
content: I have jigging reel where the display powers on but only shows black with a few vertical colored lines. No numbers or characters appear.Has anyone seen this before or knows how to fix it?Thanks!

author: benj38
author_rank: Frequent Contributor
timestamp: July 21, 2025, 10:45:11 pm
content: If you are lucky, this is just a display connector that is only partially attached. Open it up and remove and reattach the display connector (both ends).

author: funky2x
author_rank: Contributor
timestamp: July 21, 2025, 11:08:03 pm
content: Thanks for the tip! I already checked the zebra connector thoroughly and confirmed it’s properly seated on both ends. The flat cable connector is in good condition and has been cleaned with isopropyl alcohol.One thing I noticed is that applying heat to the microprocessor changes how the pixels are displayed — when heated, the pixel layout shifts, but once the MCU cools down, vertical lines reappear on the screen.Next to the microprocessor there is a CR2340 battery, which I measured at 0.6 volts.Given these symptoms, I’m starting to suspect it might be a firmware issue rather than purely hardware.

author: ME
author_rank: Frequent Contributor
timestamp: July 23, 2025, 03:12:12 pm
content: As that battery is dead why not replace it for a start?.

author: MathWizard
author_rank: Super Contributor
timestamp: July 24, 2025, 03:01:20 am
content: jigging reel ? For fishing? What does the screen show ??

author: Psi
author_rank: Super Contributor
timestamp: July 24, 2025, 03:10:19 am
content: Capacitors look ok?
Dissolving stackup adhesive in polyimide flex board? - Page 1
Forum section: electronics / repair

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: June 23, 2023, 11:41:22 pm
content: I have a 4 layer poly flex board that has an inner trace that needs repair, if at all possible. The trace in question has mechanical damage.I thought about digging in with a dremel and abrasive brush, but I think a drop or two of the right chemical to clear the area would be much preferred since the copper is insanely thin. I've tried acetone already, does nothing.Anybody know what dissolves the adhesive layer?

author: thm_w
author_rank: Super Contributor
timestamp: June 24, 2023, 12:05:40 am
content: https://www.mclpcb.com/blog/adhesive-vs-adhesiveless-polyimide-flex-core-material-types/Says here acrylic or epoxy, but acetone should work on those.It might be adhesive-free, in which case not much you can do with solvents AFAIK.https://www.pcbonline.com/blog/multilayer-flex-pcb.html

author: AUBI
author_rank: Newbie
timestamp: July 18, 2023, 07:51:24 am
content: You may need this kind abrasive brushhttps://www.aubibrush.com/silicon-carbide-moulded-deburring-disc-brush

author: kingswoods
author_rank: Newbie
timestamp: July 18, 2023, 09:25:07 am
content: The best solvent for most soluble adhesives is white spirits. I note you're in the USA so it might be called mineral spirits there. Its not turpentine.

author: marhuum
author_rank: Contributor
timestamp: July 18, 2023, 11:37:59 pm
content: almost all the time when come to dissolving work, the nail polish remover is immediateits most filler is acetone, precisely most are: Isopropyl acetone, methyl ethyl ketone, and n-methyl-pyrrolidone
"DIY" Branson EC Ultrasonic Solution Idea (?) - Page 1
Forum section: electronics / repair

author: KatLab
author_rank: Newbie
timestamp: March 22, 2022, 09:02:17 pm
content: Hey guys!CAUTION, LOTS OF TEXT AND LOW REDACTION SKILLS, ENGLISH IS NOT MY NATIVE LANGUAGE lolSo, i've been looking for Branson EC or some good alternative in my country since i started on Electronics Repair (like 5 years ago) with zero luck. Last year i tried to import a Gallon, but dealing with chemicals and the weight of that thing, shipping got expensive really fast. so i tried asking big repair shops where do they get the ultrasonic cleaning solution for water damaged phones and stuff, and turned out that EVERY SINGLE ONE(even Reifschneider, that's an official apple repair shop in Chile) told me they just use IPA mixed with water or just plain IPA in the Ultrasonic bath.From my humble experience in water damaged phones, demineralized water and IPA only works for removing Flux and gunk, and using pure IPA in the tub is just an accident waiting to happen.THE ACTUAL QUESTION STARTS HERESo i started searching for the Branson EC formula, and came across with the Safety Data Sheet, and found out that Branson EC is 70-80% Monoethanolamine, 5-10% Morpholine and the rest is just water. Monoethanolamine is an industrial alkaline detergent and Morpholine is mostly used as a Ph stabilizer. I can buy a 1 liter bottle of 99% Monoethanolamine for like 15 USD. Could it be possible to use Monoethanolamine as a Branson EC in my ultrasonic bath? or am i just being too much of a cheap bastard? i could seriously start a new "Branson EC Cheap Alternative" business here in Chile if this works, but i wanted to ask you guys what you think.thanks and sorry about the messy redaction

author: jenders
author_rank: Newbie
timestamp: July 30, 2025, 07:39:45 am
content: Curious about this as well. It seems that Branson EC cleaner has either been discontinued or hit hard from the US tariff situation. The price has nearly doubled while Monoethanolamine and Morpholine seem to still be reasonably priced.
Finished!--DIY Instek GSO-810 Replacement Handle - Page 1
Forum section: electronics / repair

author: cliffyk
author_rank: Frequent Contributor
timestamp: January 11, 2022, 02:36:17 am
content: NOTE: I just moved this from theProjects, Designs, and Technical Stuffcategory where I had originally, and incorrectly, posted it...As has happened with many of the older Instek instruments from the mid-late 90s (spectrum analyzers, oscilloscopes and other) that shared the same cabinet configuration, the plastic handle on my GSP_810 failed when it became brittle and the locating pins on the hubs sheared, and the hubs themselves cracked and fell apart.However t'other day it occurred to me that I could use FreeCAD to design new hubs in such a manner that a length of aluminum flat stock could be fastened to a couple of the same to make a new handle. I got the design finished yesterday and 3D printed a prototype for final fitting last night. After a few tweaks of the design I have produced two hubs (see below for a couple "screen grabs" from FreeCAD:(inner side showing the central post and 12 locating pins)(outer side showing the slot for mounting the handle to fabricated of ¾ x ⅛ aluminum flat stock to be fastened with small sheet metal screws)I plan to reinforce the long span of the flat stock handle by laminating a couple of ¾ x ⅜ oak "pads" to it.I will update this post when it is done.If anyone wants either the FreeCAD design or .stl model files give me a yell and i will post links to same.Here is a screen shot of a pair of the hubs, with supports, and ready for slicing created using theChitubox3D model manipulation and "slicing" application:I use an Elegoo Mars (upgraded to a Mars Pro) printer, and a 50/50 mix of WeistekTenaciousresin (clear) and theirStandardresin (gray) to obtain the desired detail and mechanical characteristics. TheTenacioushas an elongation-at-break of 50% or better, theStandardEoB is 11-20%. Both are are the best I have found and reasonably priced too.Here's a photo of the two hubs printed, fully cured, and cleaned up (I am going to paint them in ivory to match the cabinet):Still in progress, I got slowed down by some health issues--gall bladder had to come out...Update 01/12/2022:Got it done! here's some photos:head on:right side hub:left side from top:left end of oak handle:Right side hub:front view with handle folded back:I think it came out pretty good all things considered--time to get it listed on eBay...
DJ Light sound to light mode fault - Page 1
Forum section: electronics / repair

author: ajp8868
author_rank: Regular Contributor
timestamp: August 20, 2020, 05:03:30 pm
content: Hi All,I'm trying to repair an issue on one of my DJ lights which appears to have randomly developed a fault. When it first happened, it was just continually reacting very, very fast which first lead me to believe the microphone was broken (it was rusty so I assumed). I replaced this but no help.So that lead me to believe there was a short on one of these MOSFETs. I tested and sure enough one of them was shorted. I was probing while powered on (stupid I know) and I shorted the gate and source on one MOSFET which caused the light to completely stop reacting. So I replaced two identical MOSFETs, but still the same, no reaction.I've measured each resistor and they all report the correct values, I've also checked each capacitor (out of circuit) and they seem fine. Lastly I replaced one of the T4 diodes as this tested as 0l in both directions out of circuit. Nothing has helped and it currently doesn't react at all.If I place my finger on the board in different places it starts to react really fast again which I believe is because I'm conducting and may e shorting something.Any help would be appreciated, thanks!

author: ajp8868
author_rank: Regular Contributor
timestamp: August 23, 2020, 03:50:30 pm
content: Can anyone help please?

author: DaJMasta
author_rank: Super Contributor
timestamp: August 24, 2020, 03:11:21 am
content: Do you have an oscilloscope? Shorting pins on a mosfet could mean its switched voltage could have been shoved down the gate line, which means the thing controlling it may be dead - my guess is a pin of that micro. If that's the case, no signal should be present on the gate of the mosfet, and that would be why it's not reacting.If there is signal there, then maybe it's something to do with the power of the mosfet or damage to what its switching.

author: ajp8868
author_rank: Regular Contributor
timestamp: August 24, 2020, 08:06:28 am
content: Thanks for the replies. Sadly I don't have a scope yet, that will have to wait till I have a garage..I've attached a couple of pictures of an identical light with a much cleaner board and circled the MOSFET I shorted.If there was no signal being generated from the micro anymore, would it still react when I touch parts of the board, mainly above the MOSFET where the caps and diodes are..?
DJ Mixer, Wrong Voltage, Need Help Identifying Failed Part : Solved - Page 1
Forum section: electronics / repair

author: Timmox
author_rank: Contributor
timestamp: July 24, 2024, 02:08:40 pm
content: Hi all,Thanks for taking the time to help.I'm repairing an Allen and Heath XONE 23 DJ mixer that had the wrong power supply connected to it. It runs on 12V but got 24v. I have replaced one of the voltage regulators but am struggling to identify another. It is marked AX06 17. I don't have a schematic but I've deduced it's turning the 12v into a 3.3v rail.I have marked where it is on the second photo with a red line.Any help as always will be gratefully received.Cheers,Tim

author: fzabkar
author_rank: Super Contributor
timestamp: July 24, 2024, 03:33:23 pm
content: AOZ1280CI, Alpha & Omega, buck regulator, 3V - 26Vin, 1.2A, 1.5MHz, marking AXxx, SOT23-6L:https://aosmd.com/res/data_sheets/AOZ1280CI.pdf

author: Timmox
author_rank: Contributor
timestamp: July 30, 2024, 09:11:46 am
content: @fzabkarYou absolute legend! Thank you so much.
Dji phantom 4 drone battery reset  - Page 1
Forum section: electronics / repair

author: DONETOP
author_rank: Newbie
timestamp: October 24, 2022, 11:27:49 pm
content: Hello guys! Pls I am new here and seek your help to solve an urgent issue for me. I have this clone type ev2400 chip connector which i used with bq studios to clear pff flag error. In deed the pf flag error was cleared and show turned from red to green . But when I plug in the aattery to the drone it tells me tells me battery error and cell broken. The battery has four cells and all the four cells voltages are read 4100mv each when I use the ev2400. But to my surprise when I use the nlba1 software to read the battery, it's status says locked.I only have the bq studio to do this work because it does not require licensing. Pls what have I not done well. If you have suggestions to what I should do pls drop the steps too..Thanks
Dk124 and switching transformer help  - Page 1
Forum section: electronics / repair

author: Australia-learn
author_rank: Contributor
timestamp: May 10, 2025, 10:21:29 pm
content: Hey guys. Trying to get a switch mode PS running. Having unusual amount of trouble with the aux voltage circuit.The original DK chip exploded.So runs a DK124 8 pin chip. Its getting the full 320v DC. Yet it refuses to switch. Not seeing any feedback either. I do know the capacitor connected to the feedback is important and it won't switch without it. But ive swapped it a few times also they test fine..I've replaced the chip 3 times. No change. Its wanting to switch.(as in you can see it teying) Yet just wont. (5v DC on hot side of octo)Feedback including all resistors diodes and octos test fine.Basicly need 12v Dc. And plus and minus 9v dc from this circuit.I cant yet fully understand this complete circuit. However its just a tl494 that runs in the secondary section. But I believe its getting its power from from a slightly different area than what I really need right now.I need to get the main IC up and running (plus and minus 9v)so I can then monitor switching on the 494. I can just feed the 494 off a secondary 12v supply.Im a bit of a noob. So can't fighure it out. There are lots of independent grounds that I assume have to be that way for whatever reason.Im happy to rip this transformer out and build my own circuit. For the aux voltages. However I only have 30+V transformers here. And im not confident to rewind them. Plus im not very clued up on the drive circuit or its feedback sruff.Ps is a ali express thing. No info on it. Little bit like the wamptek ones. Just the aux voltages have moved around a bit.Any magical ideas? I have a few switching ics here. And transformers but there all 30+ v. And i don't have any buck converters. Only boost. So convenient right? Haha.Tried to get a clear photo but phone is being a pain.