hybridfree/eevblog-posts huggingface dataset:
I2C Solder Station  (JBC KNOCK OFF) - Page 1
Forum section: electronics / repair

author: GeoSaffer
author_rank: Newbie
timestamp: February 27, 2022, 08:59:38 am
content: I have had these I2C solder stations for a few months now and they both and they both died on me at the same time.I looked at the back and saw the fuse box pulled it out and for sure the fuse is blown. I replaced the fused with the supplied extra fuse made sure that the switch is off and then plugged the power cord in. at that moment the solder station turned on for a split second and off again. Thought that was weird but ok let's turn it on,.....and nothing, pulled the fuse out and it was blown again.OK.....So now we have a short for sure. Tracked down shorted component and pulled it off the board, under it on the PCB is a diode marking. On the component, is a marking "CP".So this diode runs from 24v pin to 0v pin on the 24v ac line coming from the toroidal transformer. I have no idea what to replace it with.Any suggestions would be much appreciated.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: February 27, 2022, 09:22:15 am
content: might be TVSTry test by e.g. a circuit like the followingfirst low Vaa then gradually adjust Vaa voltage via the power supply. Use a universal meter or DMM 29 to test the voltage across D1, as shown. When the D1 voltage stops following the increase in Vaa voltage, this voltage should be your TVS breakdown voltage.
Ibanez Combo Amp: Unusual Input Jack - Page 1
Forum section: electronics / repair

author: Helmanfrow
author_rank: Contributor
timestamp: December 22, 2022, 05:32:15 pm
content: I have an old Ibanez SWX20 instrument combo amp with a broken input jack.This would be a simple repair save for the fact that I am unable to find a suitable replacement part.The shunt mechanism on the original jack is sprung on the left and opens on the right.All the other jacks I've seen so far have this reversed, opening on the right.Installing one of these would send the signal to ground.Here's a typical jack found online:Here's an album with photos of the amp PCB in question:https://photos.app.goo.gl/5RV1Q1o6ku96uLPp9You'll notice in the photos that there is a metal grounding collar around the input. I believe this is for chassis ground, which is kept separate from signal ground by passing it through a capacitor. I haven't removed the jack yet but it appears to be a separate part.I realize that a little creativity can get me around this but I'd rather find a matching part before resorting to hacks.I've contacted Ibanez but I have not yet heard back from them.I'm hoping someone here has the resources to help me find the right replacement part.Anyone?

author: David_AVD
author_rank: Super Contributor
timestamp: December 24, 2022, 01:32:30 am
content: That looks like a Cliff S2 series socket, of the type BBBPCCBBB = break, break, break contactsPC = PC pinsC = pin in centre (other version is A where the pin is towards the front of each tab)

author: Helmanfrow
author_rank: Contributor
timestamp: April 19, 2023, 11:18:39 pm
content: Turns out that Ibanez stocks these parts. I ordered one through a local dealer. It took like two months to get to me but I finally got it and made the repair. All good.
IBM 5170 power supply repair, 3Hz voltage spikes on all rails - Page 1
Forum section: electronics / repair

author: dmuntz
author_rank: Newbie
timestamp: July 25, 2022, 08:55:59 pm
content: I have a couple of IBM 5170 power supplies that are exhibiting similar symptoms. The DC voltages all have a lot of noise, varying by 0.1 - 0.2V according to my BM786 EEVBLOG(tm) meter, also the negative rails are "high" (-3V on the -5V rail, and -10.5V on the -12V rail). The interesting bit is that I took a look at the DC output with an oscilloscope, and all the rails have a very regular ~3Hz voltage spike that seems to account for the variability seen with the meter. I thought someone might recognize this symptom and be able to point me in the right direction.In one of the supplies, I've replaced 3 blown WIMA caps (that was all of the WIMA caps), and am mid-recapping a bunch of 1200uF and 820uF caps that were way out of spec. By lucky coincidence, both of the supplies are almost identical to the one described in the SAMS for the 5170 (http://vtda.org/books/Computing/Hardware/Sams/Sams%20-%20IBM%205170%20-%20with%20type%201%20motherboard.pdf). These PSs use 3 LM339N voltage regulators, an LM358N op amp, a D83-004K diodes (mentioned because they're attached to huge heatsinks), a pair of 2SC3320 power transistors (also heatsinked), and two additional transistors: 2N2222 and 2N5682.

author: RoGeorge
author_rank: Super Contributor
timestamp: July 25, 2022, 09:23:58 pm
content: With old electronics, the electrolytic capacitors might have dried. I would change them all anyways, but I'm not familiar with that model so this is only generic advice.0.1-0.2 V ripple might not be that much, but the absolute voltage seems way off. Some power supplies can not stabilize well without a load. Was there any load attached to the power supply while measuring it?

author: dmuntz
author_rank: Newbie
timestamp: July 25, 2022, 09:55:31 pm
content: I knew I forgot to mention something. It was tested with load (25r 50w on the 5v rail). These PSs will shut down w/o load. I don't know what IBM was thinking, but these have an absolutely stupid number of sizeable electrolytic caps. I think it was 17 large-ish ones in the 820uF-1200uF range (~1cm diameter, ~5cm high), 2 large ones 1000uF 200V, and another 10 or so small ones.
IBM PS2 keyboard cable - replacement of 6 way SDL connector. - Page 1
Forum section: electronics / repair

author: perdrix
author_rank: Frequent Contributor
timestamp: October 06, 2023, 12:23:22 pm
content: I have an original "buckling spring" IBM PS2 keyboard with an SDL socket for the keyboard cable. The original cable is now intermittent and I am sure that this can be fixed by cutting off the original connector with an inch or so of cable and fitting a replacement connector.The problem is that I suspect these can only be crimped with the very expensive TE crimp tool. Has anyone replaced these connectors successfully without using the special crimping tool?Alternatively does anyone (in UK/Europe ideally) have a known good 6 way SDL to PS2 cable that they would part with for not much money?ThanksDavid

author: aeg
author_rank: Regular Contributor
timestamp: October 06, 2023, 11:03:54 pm
content: You may already know this but Unicomp sells the cables.https://www.pckeyboard.com/page/product/1398094Not in the UK and might be more than you wanted to spend, however.

author: pandrew
author_rank: Contributor
timestamp: October 07, 2023, 12:34:50 pm
content: I've done that, with a thin flat head but heavy duty screw driver, it had the same width as the pin itself, but was heavy duty enough that I probably put something like a quarter to a half of my body weight onto it, and I also added a little bit of longitudinal rocking motion to make it fully enter. Be very careful not to allow the screwdriver to slip, or it will deform the connector, and you may even hurt yourself. What may be even more finicky than the pins is the strain relief plastic which is supposed to click into place. But to be honest if that one won't click it's not the end of the world cause the main strain relief comes from crimping metal around the cable. And the metal crimping can be done with any generic hexagonal crimper tool.Now all that being said, it doesn't make financial sense to do this, the connector is made out of:Plug: 1-520424-2Bottom shield: 520463-1Top shield: 520462-1Ferrule: 520435-1And you need to buy all of these separately.You can probably skip the ferrule, and use some more improvised piece of metal and some heat-shrink instead, for a slightly less solid result.The last I looked the sum of these components was more than the cost of an entire cable from Unicomp.I guess maybe it makes some sense if you want to make your own custom cable that is somehow different, and don't want cut up a Unicomp cable to do it.

author: perdrix
author_rank: Frequent Contributor
timestamp: October 09, 2023, 07:26:20 am
content: I managed to cut the ferrule and salvage the top and bottom shields. I ordered a replacement plug and ferrule direct from TE (less than 10 dollars in total).All the necessary parts except the bottom shield can be ordered in qty. 1. Sadly the MOQ for the bottom shield is 2000I've contacted TE to see if that MOQ restriction can be lifted.ThanksDavid
IC find DCDC LCD bosh DCU 220 - Page 1
Forum section: electronics / repair

author: salviador
author_rank: Regular Contributor
timestamp: February 07, 2023, 11:23:43 am
content: I'm fixing the LCD monitor of a bosch DCU 220 notebook, the problem is LCD flicker it's not a LED backlight problem but it's a DC/DC problem that drives the LCDI can't find this IC: (00=3G42L

author: fzabkar
author_rank: Super Contributor
timestamp: February 07, 2023, 07:17:38 pm
content: The marking style is Richtek's.Several candidates here:http://www.smdmark.com/en-US/search/code?id=00%3D
IC Identification 16pin - From A Li-Ion Dual Charger - Page 1
Forum section: electronics / repair

author: hugo_g
author_rank: Newbie
timestamp: April 21, 2022, 10:43:14 am
content: Got this from a teardown of a dual 8.4v Li Ion camera charger. It's an unbranded charger from China. The markings were on the underside of the IC. The top was non-marked.I thought it might be a ADP3801/ADP3802 or some kind of clone. The datasheet of that seems to meet the chargers capabilities.I've tried googling for an hour or so but I can't find anything. I'm thinking the markings mean something generic.Anyway I'm putting this out there in case these markings mean something to someone.Any help is welcomed. Thanks

author: fzabkar
author_rank: Super Contributor
timestamp: April 22, 2022, 08:04:35 pm
content: This image shows the underside of an ADP3801:https://cdn.shopify.com/s/files/1/0103/5124/7415/products/222315700494-1_1200x1200.jpg?v=1572404695

author: hugo_g
author_rank: Newbie
timestamp: June 19, 2022, 10:11:35 am
content: Thanks for that picture of the underside of a geninue ADP3801/ADP3802. I'm going to lock in a clone/ghost shift/etc of a ADP3801/ADP3802. Might even be an unmarked geninue and for some reason it wasn't labeled (didn't meet QC, etc).The top side of the IC matches as well with the little indent.
[Solved] IC identification - Page 1
Forum section: electronics / repair

author: mnt22
author_rank: Contributor
timestamp: February 24, 2021, 08:59:07 am
content: Hi everyone please help me out with this IC identificationthe marking are "l244" "h33" "GBV".Thanks for the help

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 24, 2021, 10:40:29 am
content: Looking at the surrounding components this seems a good guess:https://www.tme.eu/Document/f395a7fa3a17d720ac12422448ebdbea/ACPL-244-500E.pdf

author: amyk
author_rank: Super Contributor
timestamp: February 24, 2021, 02:15:44 pm
content: More likely to behttps://media.digikey.com/pdf/Data%20Sheets/Lite-On%20PDFs/LTV-214,244.pdf

author: mnt22
author_rank: Contributor
timestamp: February 24, 2021, 03:01:36 pm
content: Thanks PA0PBZ and amyk

author: fzabkar
author_rank: Super Contributor
timestamp: February 25, 2021, 07:34:07 pm
content: http://www.smdmark.com/en-US/search/code?id=244
IC Identification - Page 1
Forum section: electronics / repair

author: Gonzini
author_rank: Contributor
timestamp: March 16, 2023, 11:56:04 pm
content: Hi guys.Anyone know what U4 might be in the attached pics? I read A3901 which comes up as a dual full-bridge motor driver which doesn't seem to make sense in this application. Also the track layout doesn't stack up to be one of those from what i see. I know these IC's can be used for other applications, but just seems a bit out there.Board is out of some music gear which the audio outputs fail, its a common problem with them.Its part of the power supply, looks like a split supply going by the PCB layout. You would think it would be a regulator or switching mosfet maybe.Cheers

author: amyk
author_rank: Super Contributor
timestamp: March 17, 2023, 12:08:53 am
content: TPS7A3901

author: fzabkar
author_rank: Super Contributor
timestamp: March 17, 2023, 01:04:36 am
content: https://www.ti.com/packaging/en/docs/partlookup.tsp?partmarking=a3901

author: Gonzini
author_rank: Contributor
timestamp: March 17, 2023, 05:26:31 pm
content: Cheers guys, makes sense nowThat was exactly what i was expecting it to be. I'm not used to these devices so a bit hard to track the full part No. down if you don't know!
IC Identification NEC 551E3Y1A - maybe? - Page 1
Forum section: electronics / repair

author: fdk
author_rank: Contributor
timestamp: July 07, 2023, 11:31:18 am
content: Hi all,I've been trying to find out what this IC is for a while now, it is inside a Yashica Electro 35 FC. I had someone suggest that it was a transistor package, based on some info for a different model, but I don't know if I fully agree with that. There are 3 other silicone transistors elsewhere, which I think are the replacement to earlier transistors (Germanium?) from earlier models.If you look at the photo, it is a 10p DIP with only 6 pins connected.https://i.ibb.co/SNHpf58/IMG-20221204-000438.jpgDate is around late 60's early 70's. Probably 71 or 72 this model camera was updated, probably to the Gxseries.I'm not really sure of the purpose of this IC, but I suspect it is something to do with the light sensor which lights up 2 different arrows to indicate either under or overexposure. A datasheet would probably give a clue but I have found nothing so far. Camera is currently overseas, so I can't do any testing, though I am semi inclined to buy another just to try and figure it out!The real reason I had it apart was to see if it was possible to fit a small rechargeable battery in place of the original mercury containing batteries (it is).So I hoping someone might have a clue what this IC is, and perhaps a datasheet that can help figure out if it is working or not. Thanks!

author: fzabkar
author_rank: Super Contributor
timestamp: July 08, 2023, 12:46:36 am
content: It doesn't help, but the part number prefix is probably "uPC".QuoteI had a cursory look here, but I couldn't find anything:https://mirrorservice.org/sites/www.bitsavers.org/components/nec/_dataBooks/

author: fdk
author_rank: Contributor
timestamp: July 08, 2023, 04:19:13 am
content: Thanks very much for the link, I had bee looking for some kind of catalogue but couldn't find anything. It doesn't help there is an NEC TV or monitor with model number 551..I'll dig through an see if I can find anything.

author: amyk
author_rank: Super Contributor
timestamp: July 09, 2023, 02:56:47 am
content: uPC55 is an op-amp, which seems close to the purpose of your part. Given the date, I suspect whatever documentation exists on it is likely to be in Japanese only.

author: Shonky
author_rank: Frequent Contributor
timestamp: July 09, 2023, 05:06:15 am
content: This manual has some schematics. Does this line up with the board?https://www.manualslib.com/manual/1174739/Yashica-Electro-35.html

author: fdk
author_rank: Contributor
timestamp: July 09, 2023, 12:20:36 pm
content: That one is a different, maybe earlier, model. There are enough differences to think it's not as simple as substituting one part for another. As amyk suggested, my thoughts were maybe an opamp of some sort, but I don't know how test that theory.
IC part no  - Page 1
Forum section: electronics / repair

author: RECO395
author_rank: Newbie
timestamp: January 11, 2025, 11:55:48 am
content: Could any one help me to find the part no of this SMT CI marked CGHM ?

author: ercan4434
author_rank: Contributor
timestamp: January 11, 2025, 12:46:43 pm
content: Can you identfy where the pins connected to and post a photo with surrounding components

author: Dougmc
author_rank: Contributor
timestamp: January 11, 2025, 01:11:57 pm
content: It the g is a 6A 6hmhttps://www.repaircompanion.com/smd_code_search/6hm?package=&pin_count=&manufacturer=
IC SMD offline LED controller - Page 1
Forum section: electronics / repair

author: salviador
author_rank: Regular Contributor
timestamp: July 28, 2021, 09:38:12 am
content: what is this component IC 6 pin SMD?, the datasheet is not foundIt is of an offline LED controlPIN4 looks like the gate command for the mosfet

author: fzabkar
author_rank: Super Contributor
timestamp: July 29, 2021, 06:29:45 pm
content: Can you tell us the markings on the other semis and passives? This would help us to determine which numbers represent date codes.

author: salviador
author_rank: Regular Contributor
timestamp: July 30, 2021, 08:26:57 am
content: It is a step down converter type

author: fzabkar
author_rank: Super Contributor
timestamp: July 30, 2021, 10:20:30 pm
content: I'm trying to eliminate date codes from the markings. For example, is "613" a YWW date code (eg week 13 of 2006 or 2016)? You could possibly answer this question by examining the date codes on the capacitors or MOSFET.Also, I can't see how the IC connects to the supply negative.

author: salviador
author_rank: Regular Contributor
timestamp: July 31, 2021, 08:31:38 am
content: you're probably right it looks like week13 2006so it's the date, I got confused thinking it was the codecexactly the mass! , This IC seems that it exploits the voltage drop in the mosfet + shunt resistortheoretically the mass looks like it is in pin 2The mosfet

author: fzabkar
author_rank: Super Contributor
timestamp: July 31, 2021, 05:46:27 pm
content: http://www.1mos.com/upload/file/AUK/SMK0465FJ.pdfThe second line of the MOSFET markings is "GYMDD".G : Factory management codeYMDD : Date Code (year, month, date)76907 -> Sept 07, 2006/2016
IC ?: SMD sot-23-6 with marking 33p2x - Page 1
Forum section: electronics / repair

author: Oleander
author_rank: Contributor
timestamp: May 30, 2025, 11:40:20 am
content: Hi all,I am looking to identify a SMD sot-23-6 smps controller on the failed PCB that I got yesterday to fix. Its marking is 33p2x. The SMPS was fitted in refrigerator. What I already know, is that this IC and main power mosfet failed with with some resistors around.Maybe anyone could point me to the producer of this IC? It is probably from far east ...

author: Vovk_Z
author_rank: Super Contributor
timestamp: May 30, 2025, 12:14:03 pm
content: Can you drop a photo of PCB with this IC and surroundings?(I don't know this IC but a photo can help somebody).

author: fzabkar
author_rank: Super Contributor
timestamp: May 30, 2025, 02:42:01 pm
content: https://electronics.stackexchange.com/questions/733632/component-identification-33xxx-sot23-6https://wmsc.lcsc.com/wmsc/upload/file/pdf/v2/lcsc/1810181625_Sifirst-SF5533LGT_C261343.pdf

author: Oleander
author_rank: Contributor
timestamp: May 30, 2025, 07:33:08 pm
content: Thank you fzabkar ! Bingo ! In the 1-st link there are also pics, showing the same PCB like mine.
ICE 680R Supertester Multimeter - Page 1
Forum section: electronics / repair

author: German_EE
author_rank: Super Contributor
timestamp: March 17, 2016, 11:00:00 pm
content: One of these was handed to me yesterday as a dead unit, it also had a needle that stuck at 80% of full scale. The meter needle was tackled first by removing the back of the meter then carefully unclipping the clear plastic front. By slipping a piece of paper underneath the needle it was possible to bend it upwards slightly so that it would travel across all of the scale. When clipping the front back into place make sure that the X2 button lines up with the hole.The meter was however still dead, no reading on volts, amps or ohms. Eventually it was found that BOTH test leads were open circuit so I'm now waiting for some 1mm silicone wire to arrive so that I can complete the repair.

author: rudio
author_rank: Newbie
timestamp: September 19, 2021, 03:26:29 pm
content: Hi,schau mal hier:https://www.eevblog.com/forum/chat/show-your-multimeter!/msg3697969/#msg3697969Ich habe übrigens auch eines, beginne gerade, es zu restaurieren.Gruss R. (25km nordöstlich DA)
Ice Maker Pump Repair - Page 1
Forum section: electronics / repair

author: electricMN
author_rank: Regular Contributor
timestamp: April 27, 2020, 11:23:55 pm
content: Anybody know what manufacturer makes this driver chip? It's marked with "477H" & "8YBG". It's used to drive a 12VDC pump motor used in a counter top ice maker. The motor has four coils. The junction of two of the coils is tied to GND, another junction is tied to one of the outputs, another junction is tied to the other output and the last junction isn't tied to anything.

author: Manul
author_rank: Super Contributor
timestamp: April 28, 2020, 12:01:01 am
content: Not sure about manufacturer of original one, but it is hall effect sensor for example AH477AZ4 from Diodes Inc.

author: electricMN
author_rank: Regular Contributor
timestamp: April 28, 2020, 04:10:09 am
content: Quote from: Manul on April 28, 2020, 12:01:01 amThank you very much.

author: Whales
author_rank: Super Contributor
timestamp: April 28, 2020, 05:47:26 am
content: Many 12V computer fans are of a similar design, one weird-skinny-looking chip that controls the coils and uses hall sensing. The ones in fans are probably lower wattage/current than what you will find in a water pump, however.Hope you find a working replacement

author: james_s
author_rank: Super Contributor
timestamp: April 28, 2020, 06:23:48 am
content: You can find rackmount server fans that are quite powerful. I have some that I pulled from a scrapped Dell 2U server that draw something like 2.5A.

author: electricMN
author_rank: Regular Contributor
timestamp: April 29, 2020, 03:41:04 pm
content: Quote from: Whales on April 28, 2020, 05:47:26 amI haven't found an exact replacement but I've ordered a couple to try. I can get a new pump for $15 but it's not in stock anywhere so I have to wait until it is. In the mean time I thought I'd take a stab at repairing the pump. I don't even know if the driver chip is the problem but they're cheap so it's worth trying.

author: james_s
author_rank: Super Contributor
timestamp: April 29, 2020, 04:28:33 pm
content: There isn't much else to go wrong, if the shaft spins freely and the coils don't smell burned then it's probably just the IC.
iCharger 458Duo repair - Page 1
Forum section: electronics / repair

author: EgOPhil
author_rank: Newbie
timestamp: May 12, 2025, 10:41:01 am
content: Hello everyone,I have a defective iCharger 458Duo. When I power on the device, I have a slight beeping noise from the coil (green). The IC labeled “D4W28” gets hot after a few seconds and the iCharger stays off.I have measured the components around the ICs “AL114” and “D4W28” and they are all OK.However, I have the problem that I cannot find the ICs outlined in red and therefore have no data sheet. Do any of you have an idea whichchips might be involved?Thank you very much,Phil
Icom 222 mhz radio disaster IC-375 - Page 1
Forum section: electronics / repair

author: WB8PFZ
author_rank: Regular Contributor
timestamp: February 02, 2025, 01:52:00 pm
content: Without getting into the gorry details, I believe 120 volts was applied to the 12 volt bus for a very short time. The radio is stuck in transmit mode, but all functions seem to function. I found the connection on the main board that has a voltage drop from 13 to 8 when it is connected. So looking for a short that is dragging down that supply rail. Not a ton of components but looking for any secrets in locating the short. Thanks for the help.

author: benj38
author_rank: Frequent Contributor
timestamp: February 03, 2025, 02:34:33 pm
content: A few options immediately come to mind:Thermal CameraPage 2 here:https://xdevs.com/doc/HP/pub/HP-Bench-Briefs-1986-03-04.pdfSometimes shorted tantalum capacitors squeal faintly. In a very quite room you can hear it.

author: ftg
author_rank: Frequent Contributor
timestamp: February 03, 2025, 05:00:15 pm
content: For those of you who want a quick look of the device schematic, the service manual can be found here:http://www.radiomanual.info/schemi/ICOM_VU/IC-375A_serv.pdfThere seems to be plenty of Zeners and regulators connected to the 13.8V rail, so many contestants for quick destruction from 120VAC.But I'd echo benj38's suggestion of a thermal camera. That's the secret to debugging shorts.

author: WB8PFZ
author_rank: Regular Contributor
timestamp: February 03, 2025, 09:51:26 pm
content: When I unplug the main board I can power up the radio. I have the current set low on my power supply and when I plug the main board in it drops to 7-8 volts. That's when I shut it off.

author: metrologist
author_rank: Super Contributor
timestamp: February 03, 2025, 10:38:08 pm
content: Quote from: benj38 on February 03, 2025, 02:34:33 pmLoL

author: WB8PFZ
author_rank: Regular Contributor
timestamp: February 04, 2025, 10:39:31 pm
content: Found 4 or 5 transistors in the keying section bad. On order.
icom HM-100N mic - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: November 18, 2021, 07:14:48 pm
content: Hi all,ive an icom ic-f1010 on 2 meters,the mic seems to of given up the ghost,would anyone have a schematic for one,ive hunted all over but cant find anything,its funny it says condenser microphone on the rear but has a 5v feed to it.!TIA

author: m3vuv
author_rank: Super Contributor
timestamp: November 18, 2021, 07:45:11 pm
content: sorry,i was getting mixed up with dynamic!,all i get is a carrier but no audio.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: November 19, 2021, 12:47:28 am
content: I fix mics all the time at a radio shopMostly the problem is a bad connection at the connector going into the radio.This is most likely an Electret condenser mic, almost everything is these days, they take 5-9 volts "phantom" powerElectret capsules are interchangeable (2 pin or 3 pin)

author: m3vuv
author_rank: Super Contributor
timestamp: November 19, 2021, 03:28:29 am
content: I see a trace on the scope with audio from one side of the mic element and ground but nothing at the mic wire out where the wires are soldered onto the pcb,found a 2.2k resistor open,renewed that,now as soon as i connect the ground wire to the mic ,i get no tx audio and the radio goes into prog mode!,think maybe the issue is in the radio?,would try another mic if i can find the mic schematic,but no luck yet finding one!.

author: m3vuv
author_rank: Super Contributor
timestamp: November 19, 2021, 04:07:00 am
content: Its been a few years ago but,if i remember rightly this was hooked up to a psu that went full output,think its gone into prog mode with a mic plugged in since,the rx is good and the vfp etc,just no audio!.

author: m3vuv
author_rank: Super Contributor
timestamp: November 19, 2021, 12:47:09 pm
content: Well i traced the mice output to,the main board,it goes to an ic (25 on the schematic),its listed as TC4W66FU (TE12L),looked it up,looks like a dual bi lateral switch,any idea what that does in a mic circuit and could that be the problem,just been to see a friend who has a spare mic to test but he is out,will try tonight.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: November 20, 2021, 01:37:12 pm
content: Here is the Service Manualhttps://www.manualslib.com/manual/919184/Icom-Ic-F1010.html?page=42#manualI do not know what "resistor" you replaced. There is a 1 uH inductor in the mic audio lead. in the front unit.Go to page 42 of the manual. You can check some of the mic leads especially the power lead (VCC) 5V.IC 25 is on page 54.I did not look but is there a back up battery for the memory?

author: m3vuv
author_rank: Super Contributor
timestamp: November 21, 2021, 07:33:34 am
content: ive traced the signals thry to ic s5 ,it stops there!,i assume its dead but cant find a replacement,i have the service manual .

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: November 21, 2021, 02:16:39 pm
content: Try Ebay UKThis is from a US search: chip is in UKhttps://www.ebay.com/itm/254257659513?epid=1462592037&hash=item3b32effe79:g:8CIAAOSwk8xc-7V,
ICOM IC-2200H POWER SUDDEN CHANGE - Page 1
Forum section: electronics / repair

author: Armando1989
author_rank: Contributor
timestamp: June 05, 2021, 11:15:20 pm
content: Hi dudesIve noticed that my icom ic2200-h suddently change power to around 10w no matter which setting (LOW/MIDLOW/MID/HIGH) after around 5 seconds.Ive investigated diagram and measured the control voltage T1 which mandates from DAC suddently changes to 1.56v as said, no matter which was the setting.DAC is controlled by cpu via spi... so i took the scope to the clk and data lines on DAC during transmission, and bingo, after 5 seconds i found cpu ask dac to configure for this voltage:that is 000101010000 which means output 8 (t1) and value of 1.5625v when vdd is 5v and vref is 0, so that makes perfect sense.Have you any clue why cpu ask change power setting?. Ive run the calibration routine with service monitor and adjusted all fine, also default reset radio, however cpu always modify power... If only would be possible to upload fw into radio...Thanks

author: Armando1989
author_rank: Contributor
timestamp: June 06, 2021, 09:04:24 am
content: SolvedTurned to be "du" "voltage protection" setting in service menu config was not propperly saved.The way to go is push s.mw key while in tx and then power off, unplug service cable, then power on. Otherwise youll encounter this problem.Not an issue.
Icom IC-28A Memory Battery Replacement + Modification + Impressions - Page 1
Forum section: electronics / repair

author: spongella
author_rank: Contributor
timestamp: April 26, 2020, 02:15:30 pm
content: Am realigning an Icom IC-28A 2M mobile recently bought used. The old memory battery is a CR2032 with solder tabs. Got a replacement on EBay with the tabs, resoldered in place. You'll find the battery by opening up the bottom cover. The old battery was from 1999 and still holding a decent voltage and holding the memories but figured it'd be best to replace now.Radio was evidently modified by a previous owner to transmit the full receive range, possibly for MARS/CAP. Diode 21 was clipped but I fixed that just to stay legal. Or in case the radio got stolen and into the wrong hands.Output is only 20 watts versus the specs that state 25 W high, have to determine the problem as I want to use it for simplex, line of sight stuff.The radio does have CTCSS but as per the manual, only on three of the memory channels. Not a problem as I'm not a repeat user. This is a decent radio, very easy to program, good audio and to boot has an available service manual well written. Thanks for reading, any thoughts would be appreciated.
Icom ic-736 - Page 1
Forum section: electronics / repair

author: VA3vjc
author_rank: Newbie
timestamp: August 26, 2019, 12:03:41 am
content: I have a Icom ic-736 ..very pleased with it , still learning the split mode .... my Problem is the "Auto Tuner " packed it in today . meter pegs and 10 0r so seconds it kicks out ant shows THRU.. before to day it tuned without any issues ..a mobile or base ??Thanx Richard

author: njvprodux
author_rank: Newbie
timestamp: September 20, 2023, 04:29:34 pm
content: Richard, did you ever get the tuner in your IC-736 sorted? I have fixed a couple of these so might be able to help. regards Paul G3NJV

author: njvprodux
author_rank: Newbie
timestamp: September 20, 2023, 05:56:43 pm
content: This is an old thread and maybe no-one will see this but in case anyone else has the tuner problem and comes here, the first thing to check on the tuner is the motors, they can come apart inside resulting in noisy or intermittent operation. I discovered a youtube video covering this on a different radio. They can be repaired. Remove the motors and carefully open them up - the plastic parts on the rotor come unstuck. Carefully clean and glue them back together - I used superglue. I used a dot of solder to hold the casing together once finished.I also had a blown RF diode in the phase - amplitude detector section of the circuit, IIRC there are four detectors and one diode was bad. I found it by using 3 different dummy loads, one 50 ohm, one 50 ohm with a capacitor and one 50 ohm with an inductor. I used 4 different frequencies and measured the four outputs going to the CPU, 16 readings in all, then compared those readings with a similar set taken from a working tuner. This revealed the bad detector and a replacement (I used 1N7411) restored normal operation.73 Paul G3NJV
Icom IC-756 radio power connection repair - Contact source? - Page 1
Forum section: electronics / repair

author: GRFixedGear
author_rank: Contributor
timestamp: April 25, 2025, 02:52:45 pm
content: Building a new/different power lead for this old radio. Bought some amazon special connector bodies and contacts. Body is proper, but the contacts are way too big. Hotdog down a hallway. They are clearly meant for standard molex 0.093" pins. But the ones on the radio are 0.077" O.D. Picture of the side profile of the socket is shown below.The original connector body is marked JST. Female sockets AND the Male pins in the radio are stamped JST6 under the insulation strain relief clamp. I found an old Icom support document that listed their part number for the sockets as "6510003790"These are bigger than JST EL series. Larger than Molex 0.062" options. And as mentioned earlier way smaller than the standard 0.093" pins.People still make these connectors, but I dont want to buy the pre-made cables. Digikey searches coming up empty, as are Mouser and other sources.Suggestions for where I can just by a couple-dozen crimp contacts!?!?!?Any leads are greatly appreciated.
Icom ic-756 repair. Help needed to find a smd signal transformer - Page 1
Forum section: electronics / repair

author: lb7pj
author_rank: Newbie
timestamp: October 03, 2024, 05:16:35 pm
content: Hi!I have a small smd rf transformer which have given the magic smoke.. But i'm not able to find a new part and are not that into the numbers to find out even what manufacturer this is.. So help to find a LR-360 are appreciated :-)Icom number: 6140003230 Description: S.COIL LR-360Pål.

author: reef.pi
author_rank: Contributor
timestamp: October 03, 2024, 06:15:39 pm
content: You can email or better phone Icom UK, I have been in touch with them, and they are very helpful.https://icomuk.co.uk/Icom-SparesYou'll find contact details on that page.

author: lb7pj
author_rank: Newbie
timestamp: October 03, 2024, 07:29:58 pm
content: hah!I've sent them an e-mail! That should be an easy fix then :-)Thanks!
Icom IC-R7100 Battery Replacement - Page 1
Forum section: electronics / repair

author: spongella
author_rank: Contributor
timestamp: April 04, 2020, 11:52:59 am
content: Bought an Icom IC-R7100 VHF/UHF radio recently, would not hold memories when powered off. Got ahold of the repair/alignment manual on line. Changing the batteries was definitely a challenge as you have to carefully disassemble and separate the two main halves of the radio. Once opened you'll see the two CR2032 batts (see pic) under the plastic shield. One's for the memories, one's for the clock.The batteries were dead as a doorknob. Wouldn't be surprised if they were the originals. While at it am doing a complete realignment, so far only slight adjustments are needed. This radio was on my want list ever since it came out. If you have one please let me know how you like it and any experiences you've had with it good or bad.Thanks and 73's de N2HUN
Icom IC R9000 clock issue - Page 1
Forum section: electronics / repair

author: Klarkkk
author_rank: Newbie
timestamp: March 31, 2024, 05:32:19 pm
content: Greetings,i am a lucky owner of this fantastic receiver. The clock (both clock1 and clock2) are stopped. Since i would like every part of my machines to be perfect, i ask you if anyone has had a similar thing happen and how they solved it. Thank you very much, Claudio IZ0NPN

author: TheSteve
author_rank: Unknown
timestamp: March 31, 2024, 08:26:52 pm
content: Likely the clock backup battery has died.https://s873ba685ce580070.jimcontent.com/download/version/1442380267/module/4015461151/name/ic-781%20%20ic-R9000%20maintenance%20notes.pdf
icom icf-1010 pmr issue - Page 1
Forum section: electronics / repair

author: m3vuv
author_rank: Super Contributor
timestamp: September 02, 2021, 01:33:50 pm
content: Hi all,i have the above radio,it has developed a wierd fault, programing is done via the rj45 mic port it ie frequencys ctcss etc,now whenever the mic is plugged in it goes into programing mode,i have the service manual but it doesent include the schematic of the mic,its a powered electret mic ,i have a spare mic for it that i used the coily lead from to make an ethernet cable extension,when testing i found two of the wires shorted,its wierd as it looks fine,any ideas,or a link to a mic schematic as its not clear if its supposed to be like that and no signs of any joins anywhere,unless its in the thick grommet/ strain relife part where it entered the mic body,both mikes used to do the same when plugged in,as in putting the radio into programing mode,its very odd.

author: HB9EVI
author_rank: Frequent Contributor
timestamp: September 02, 2021, 02:06:02 pm
content: what mic do you have at all?the standard mic delivered with this radio is the EM-99 which is declared as a dynamic mic and not electret.though I didn't find any schematics for this mic, but the easiest way likely is to open it; much more than the mic and ptt wiring isn't there.

author: m3vuv
author_rank: Super Contributor
timestamp: September 02, 2021, 09:57:33 pm
content: aparently it should be a HM-100 or an HM-152,im not sure what mine has tho as i cant see markings on it,there is a couple of caps on the pcb inside it tho on the pcb inside it,guess there filters?
Id a diode - Page 1
Forum section: electronics / repair

author: Jester
author_rank: Frequent Contributor
timestamp: April 20, 2020, 01:57:25 pm
content: I can't seem to find a data sheet for this one:Part marked as TCI GP230Another one marked (hard to read "5H30F" ?BOM shows Semicon HV30FExpect this to be a fairly high PIV diode, perhaps 1kV or more just guessingIf anyone has a clue or a datasheet it would be appreciated

author: exe
author_rank: Unknown
timestamp: April 20, 2020, 02:06:34 pm
content: http://www.taitroncomponents.com/catalog/Datasheet/GP225.pdf?Another one idk, I'd ask the manufacturer. If you know an equivalent part, you can lookup parameters of the equivalent. I don't think general-purpose diodes are too different (for the same voltage and current ratings). May be watch out for recovery time.

author: fzabkar
author_rank: Super Contributor
timestamp: April 20, 2020, 11:32:50 pm
content: Here are the specs for the HV30F:https://datasheet.datasheetarchive.com/originals/distributors/Datasheets-X2/DSA870000-101.pdf
[SOLVED] ID early 90's international rectifier MOSFET - Page 1
Forum section: electronics / repair

author: fenugrec
author_rank: Frequent Contributor
timestamp: March 05, 2022, 09:39:28 pm
content: Hi,I could use some help trying to find info on a TO-220 mosfet on a welder control PCB.Markings :top row " 093055"middle "[IR logo] 9126"bottom "8G 1E"(see attached pic)Most ICs on this board have '91 datecodes which makes this even more confusing. There is an IRFD9120 in catalogs but no IRFD9126. I may have things backwards with 9126 being the datecode [EDIT : I now believe indeed 9126 would be a datecode) , but I don't recognize anything in the "093055" part... I doubt this is a 2N3055 since the PCB silkscreen is labeled with Gate and Source, and I don't think IR made BJTs in that period...I checked :1984 IR HEXFET databook (bitsavers / internet archive)1991 IR "HEXFET designer manual, volume 2 (doesn't cover TO220 devices though)1994 IR "Power semiconductors , Product digest 1994" (bitsavers)Any ideas ? Or anyone with maybe a late-80's databook that could take a quick look ?Thanks!

author: fzabkar
author_rank: Super Contributor
timestamp: March 05, 2022, 10:55:30 pm
content: Google Images suggests that the first line is the part number, and the second line is the date code. Standard, off the shelf parts have an alpha prefix, so this would imply that the part number is an OEM special run.

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 05, 2022, 10:57:42 pm
content: https://www.millerserviceparts.com/en/miller-electric-093055-transistormosfet-n-chan-35-a-100v-to-220ab3.5A, 100V, N channel

author: fenugrec
author_rank: Frequent Contributor
timestamp: March 05, 2022, 11:35:29 pm
content: Quote from: BrokenYugo on March 05, 2022, 10:57:42 pmWhy yes of course, I never thought of looking in such an obvious place ! I was always searching with permutations of IR, IRFD etc...Miller does like 6-digit part numbers, I should've made the connection faster.I wonder why on earth they felt the need for custom-numbered mosfets for that section of the circuit (auto-link relay control)... the more critical gate drivers are standard IRF540 mosfets anyway...Well spotted !

author: fzabkar
author_rank: Super Contributor
timestamp: March 06, 2022, 12:42:16 am
content: IRF512 meets the specs. It's in the 1982-83 IR catalogue (pages D-165, A-141).
I'd like to use very large BGA nozzles with a Weller WHA900, say 45mm X 45mm? - Page 1
Forum section: electronics / repair

author: mkinn
author_rank: Contributor
timestamp: September 04, 2025, 07:03:05 pm
content: Anybody seen an adapter to use a Weller WHA900 with the standard 850 size nozzles? I cannot find large BGA nozzles like these:https://www.ebay.com/itm/326323693011for the Weller hot air stations. Any help appreciated!

author: thm_w
author_rank: Super Contributor
timestamp: September 06, 2025, 12:12:47 am
content: You might need more power and air flow than that weller can provide, for those huge BGAs.Consider making it yourself from sheet metal, or buying a station that is compatible with standard nozzles.Not cheap:https://www.rshughes.com/p/Weller-Q10-Hot-Gas-Nozzle-Quad-Hot-Gas-Nozzle-Quad-Tip-0-709-X-0-709-In-Tip-Width-10534/037103_10534/

author: Swake
author_rank: Frequent Contributor
timestamp: September 06, 2025, 08:17:05 am
content: What is the outside diameter of the Weller thing?You might want to find or modify an adapter. Something like this:www.aliexpress.com/item/1005007386924623.html
ID of this 3-pin SMD semi? - Page 1
Forum section: electronics / repair

author: EHT
author_rank: Frequent Contributor
timestamp: March 02, 2022, 11:42:18 pm
content: In process of debuggingthis PSUI'm wondering what this IC designated A4 in the attached pic is.It is a small SMD with 3-pins and a tab. It is labelled "4A" above the line to the tab and "7J3" below the line. I'm not sure what this case style is called -maybeSOT89 - about 4mm wide.The tab is connected to the centre pin, and in the circuit this is connected to GND. The label suggests it is an IC (D, ZD, Q etc for diodes and transistors). I thought it might be a voltage reg but it doesn't have stable DC on either pin (could be a fault). I've been able to identify most other ICs and larger semiconductors in this unit and they're not that unusual. It dates back to about 2009.

author: gamalot
author_rank: Super Contributor
timestamp: March 03, 2022, 12:30:52 am
content: TL431ACPKhttps://www.ti.com/store/ti/en/p/product/?p=TL431ACPK

author: EHT
author_rank: Frequent Contributor
timestamp: March 03, 2022, 11:29:15 am
content: Excellent, thank you very much! It makes sense given where it is too.I wonder also if its possible to identify small SMD diodes and transistors that just have a 2 character marking, maybe there's a reference that helps, or is it just experience!!??

author: gamalot
author_rank: Super Contributor
timestamp: March 03, 2022, 11:47:32 am
content: Identifying an SMD is often easy, but sometimes you may need the right resources, experience, and a little luck. I usually use google and those SMD code look up sites (eghttps://smd.yooneed.one), and I also use taobao.com to search because I speak Chinese.Just upload pictures of devices you can't identify, there's always someone willing to help.

author: abdulbadii
author_rank: Frequent Contributor
timestamp: March 04, 2022, 06:31:58 am
content: prefix is got onhttps://www.electronics-notes.com/articles/electronic_components/transistor/transistor-codes-numbering.php

author: fzabkar
author_rank: Super Contributor
timestamp: March 04, 2022, 06:45:13 am
content: https://www.alldatasheet.com/view_marking.jsp?Searchword=4A
ID of this SOT23-6 level shifter in SP511e LED controller? - Page 1
Forum section: electronics / repair

author: GnatGoSplat
author_rank: Regular Contributor
timestamp: March 14, 2023, 03:14:38 pm
content: Tinkering around with my SP511e LED controller flashed to WLED, I seem to have managed to bust a pin off the GPIO level shifter IC which rendered it dead.I have since bypassed it and it still works without level shifting, but I would just like to know IF I were to repair it, what level shifter is this?Here is an image showing it (not my SP511e, but you can see people like to hack these):The level shifter IC appears to be SOT23 6-pin, has "245" marking on top. Probably not a date code, because they all say "245".Assuming dot denotes pin 1, pinout is as follows:1 - output (shorted to 3)2 - gnd3 - output (shorted to 1)4 - input (shorted to 5)5 - input (shorted to 4)6 - +5V supplyIt converts 3.3V logic to 5V. It appears to be single-supply, either single input and output or maybe they paralleled a 2-channel IC. Driving LED strip data bus, so likely unidirectional. Label on the PCB is "U4".Any ideas? AI (both Bing and ChatGPT) are absolutely no help at all.

author: fzabkar
author_rank: Super Contributor
timestamp: March 15, 2023, 02:05:24 am
content: I wouldn't call it a level shifter. To me it looks more like a dual non-inverting buffer (possibly a Schmitt trigger?). A genuine level shifter would have two supplies.TI has a couple of devices which might do the job, but their Vcc is on pin #5.

author: Peabody
author_rank: Super Contributor
timestamp: March 15, 2023, 02:45:37 am
content: It would probably be a single gate version of some 74xx245 part - HC, AHCT, LVC, or something like that. Maybe this one:https://www.ti.com/lit/ds/symlink/sn74lvc1t45.pdf

author: fzabkar
author_rank: Super Contributor
timestamp: March 15, 2023, 03:54:07 am
content: Quote from: Peabody on March 15, 2023, 02:45:37 amThe pinout doesn't match.

author: GnatGoSplat
author_rank: Regular Contributor
timestamp: March 16, 2023, 02:36:47 pm
content: Yeah, I can't seem to find anything with a matching pinout. I can't imagine they would have gone to the trouble to make a custom part.
ID required: 7611AST Buck/LED driver - Page 1
Forum section: electronics / repair

author: BreakingOhmsLaw
author_rank: Frequent Contributor
timestamp: December 29, 2024, 03:24:58 pm
content: Hello everybody.I am repairing a LED light, there's a buck/constant current driver in there I can't find any info on.Does anyone recognize the "SL" logo?

author: fzabkar
author_rank: Super Contributor
timestamp: December 29, 2024, 04:14:57 pm
content: https://www.reddit.com/r/AskElectronics/comments/1h0tbtq/what_is_this_component/https://www.lcsc.com/datasheet/lcsc_datasheet_2007030504_Hangzhou-Silan-Microelectronics-SDH7611SCTR_C601594.pdf
ID thermal fuse - Page 1
Forum section: electronics / repair

author: GLouie
author_rank: Regular Contributor
timestamp: November 11, 2019, 05:59:18 pm
content: I want to ID a thermal fuse/thermal cut out to verify replacement specs.It's from a mini convection oven used for ski boots, TFHS-2 made in Germany by K-Tech; I have the USA version. Fan operates, but no heat, and the TCO is open. It apparently ran fine for years, then quit. The heating element is stamped 1600W at 115v. There is a heat control with thermo sensor in the cavity.Pic attached, there is an "E" logo, Tf 141C, D139PT UHI searched, but did not find OEM specs. My plan is to use a NTE 8139 (141C, 15A) as it is common in the USA.

author: rvalente
author_rank: Frequent Contributor
timestamp: November 11, 2019, 07:20:24 pm
content: I could not identify it either but, 145C sounds good enough for me.