Help finding an similicar IC to repair old panasonic camcorder - Page 1
Forum section: electronics / repair

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 12:15:38 am
content: Hey everyone i got this panasonic M8 on facebook marketplace for 10 bucks, the camera as working but shutting down after a few seconds, also a lot of artifacts on the viewfiender so i begin the process of replacing the capacitors on the mainboard, everything was going well, the camera started working just fine, but in the process i managed to short the 9volts line to gnd which leads to this ic to burns itself, i cannot find anywhere, only on ebay and the shipping fee to brazil is 90usd. Can anyone healp me find and similar IC to replace ? I will leave all information that i have about it.Its called UN102 i also have the block diagram from the service manual, looks like an transistor array, pictures bellow

author: coromonadalix
author_rank: Super Contributor
timestamp: January 06, 2025, 02:04:35 am
content: https://ksp-electronics.com/en/semiconductors/integrated-circuit/un102-sip-16??look similar / like uln2003pinout to verify

author: wraper
author_rank: Unknown
timestamp: January 06, 2025, 02:13:57 am
content: QuoteThis IC is just a bunch of individual transistors in single package, it does not even have power pins. If it overheats, most likely the problem is in whatever this IC drives. Not to say you can easily check individual transistors with multimeter in diode mode or component tester.

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 02:16:01 am
content: I just shorted the 9v line using the camera without the case, this is how i know that there`s no problem que te component that the ic drives, the mainboard touched a screwdriver.

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 02:16:52 am
content: Do you think that its worth trying the uln2003 ? All options out of Brazil are very hard to get shipped

author: wraper
author_rank: Unknown
timestamp: January 06, 2025, 02:20:25 am
content: You can replace it with 4x PNP BJT. You don't need all 6 as there are two pairs in parallel, just use powerful enough substitute instead of parallel pairs. ULN2003 is 7x NPN Darlington, therefore not suitable.

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 02:24:55 am
content: Another picture of the IC with a little bit more information

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 02:26:57 am
content: Which one you recommend ?

author: wraper
author_rank: Unknown
timestamp: January 06, 2025, 02:29:40 am
content: I cannot find IC spec, but I think BC328 or similar should be powerful enough.

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 02:29:55 am
content: What about that diode in all of them ?

author: wraper
author_rank: Unknown
timestamp: January 06, 2025, 02:33:50 am
content: I'm not sure if they're actually necessary for this circuit but you could add 4x 1N4148.

author: inse
author_rank: Super Contributor
timestamp: January 06, 2025, 05:35:44 am
content: It appears to be a buck converter, that linear IC doing the control and the transistor array the power switch followed by an LC filter.So you will definitely need the diode for the freewheeling phase.Try to isolate the 9V line transistor by interrupting B and C to check whether the other transistors still work.Also use a multimeter to measure the freewheeling diodes whether they are standard or shottky diodes.If other transistors work, you could try to measure the beta to narrow down the candidates for replacement.Most probably you will have to go for SMD parts to fit it on the camcorder PCBEdit: thinking about it, probably the freewheeling diode plus transistor have failed, then the IC can‘t be saved.Thinking of the space constraints in a camcorder, I would estimate the chances to fix it without the original spare part rather low. 🙁Darlington arrays like UDN2891 are no alternative as the switching speed is too low

author: wraper
author_rank: Unknown
timestamp: January 06, 2025, 12:16:21 pm
content: Quote from: inse on January 06, 2025, 05:35:44 amIMHO it's easier to put TH parts into existing holes + common wires for emitters and anodes. With SMD you'll need adapter board.

author: yaya1956
author_rank: Newbie
timestamp: January 06, 2025, 11:22:18 pm
content: My ideia is to recreat the circuit in a small board gluing the transistors and the diodes an them solder to the existing pins. with smd parts things get a lot harder i think. the space inside the camcorder its not that smal.

author: inse
author_rank: Super Contributor
timestamp: January 07, 2025, 01:29:24 am
content: Whatever fits, fits.Some questions still to be answered before

author: yaya1956
author_rank: Newbie
timestamp: January 07, 2025, 03:20:21 am
content: My main concern is the transistors beta, i tried to measure but no lucky, since theres no other way i think i will just give it a try with the BC328.

author: inse
author_rank: Super Contributor
timestamp: January 10, 2025, 08:56:49 am
content: Did you unsolder the array to check the other channels?