Recent content by ringading

Note that this thing is littered with 2sc1345s which are on the top 10 bad transistors list. Not sure if I will replace them all - there are four on the tone amp board and 12 on another board.

Thanks analogwisdom. The culprits turned out to be the 2SC1213As. Replaced and now the crackle is gone. They tested okay on my Atlas55 but that's the fun with transistors - they can test fine but still produce noise. I haven't tried the freeze spray yet but may have to secure a can to try it...

Have a KR-5340 in pretty good cosmetic shape. Picked it up for $40 a few years ago and am now just starting to work on it. First issue was the protection relay closing. I removed both amp boards and the relay would close. I haven't done this before on any receivers - does this isolate one of...

I picked up this GE console from an estate sale. One channel works. I thought maybe there were bad transistors (germanuim) but when looking to pull the amp & tuner it appears that the wiring was messed with and one speaker isn't connected at all. Someone may have been trying to bridge the left...

Thanks cademan. Checked the transformer output earlier and seems fine and the amp board is receiving the correct voltages as far as I can tell without a SM. The fact that the left outputs are displaying the short and not the right tells me something is amiss on the left side of the amp board...

Looks like no one is following this thread (sigh). I checked the other transistors on the left channel: - 2SD438 - complimentary to 2SD438 - measured fine on my tester - replaced with KSC2690 - 2SA984 - measured fine on my tester but hfe...

Removed the screws and still shows a short. Didn't think that was it as there was more than just continuity between collector and heatsink. Guess I'll pull other transistors on the board to test.

Replaced output transistors (TIP41/42C) and emitter resistors and now it is showing a short (on DBT). On the left channel I am getting continuity between emitter and collector on TIP41 and between all connections on TIP42C (E-C, C-B, E-B) and continuity between all and the heatsink. Checked...

Comparison from alltransistors.

Meter reads 0 ohms with leads together. I will probably replace those resistors just for good measure. I have to order the transistors anyways. Or would TIP41C/TIP42C act as a good option for the outputs? I ask because I have those and don't want to wait till next week to get parts. Thanks...

Bump anyone? - see emitter resistors measuring at 1ohm instead of rated 0.5 - recommendations for replacing outputs

If I am looking to replace the outputs would you recommend MJE15030G/MJE15031G (recommended here on AK)?

Pulled the two right transistors (in photo) they tested good with my Atlas 55 - 2SB507 - 74hFE - NTE 152 - 135hFE Still no sound whatsoever. I pulled the 0.05ohm emitter resistor on the far right - tested at 1ohm. Obviously I would replace but doubt that is the cause of the issue. Do...

I assumed that 7.5 was possibly for the lights. I'll pull those two transistors tonight and test the emitter resistors and see if I can get sound from the other channel. I wish I knew where the protection circuit was but that what makes these difficult - no service manual.

Note - the potentially faulty transistor here is an NTE replacement that the owner said they replaced years ago.