I got an old kr-6600 from my cousin's barn last year and after some heavy duty cleaning I got it working and sounding great. Then, later last year, it took a while to turn on. This delay got progressively longer until it wouldn't turn on at all. After reading through the forums here, I ended up replacing all the electrolytic capacitors on the power amp board, as well as all electrolytic capacitors and transistors on the Power Amp "A" board. I did the Power amp "A" board because transistor Qk2 was getting really hot. I tested the diodes while I was doing this and they tested fine.
The replacement transistors I used were the following (digi-key p/n):
Qk1: KSA1015GRTACT, PNP, 50V, 150mA
Qk2: 2SC6144SG, NPN Bipolar, 50V, 10A
Qk3,4: 2N5210-ND, NPN, 50V, 100mA
Qk5: KSA1142OSTU-ND, PNP, 180V, 0.1A
Now the relay has no delay when turning on, a slight delay when turning off, and thumps through the speakers on both on and off. Two questions:
1. Did I replace these transistors with the right components?
2. Could the transistors I got be NPN when I ordered PNP? I have heard that counterfeit transistors have been known to make their way over here. How to check?
2. Is there some other component that can also fail that I have missed?
Thanks for all the help, I appreciate any input on this. I did all this work last November and haven't been able to use this since then, so I would like to get this going in the new year. Unfortunately, this also means that I don't remember if sound comes out of it.
The replacement transistors I used were the following (digi-key p/n):
Qk1: KSA1015GRTACT, PNP, 50V, 150mA
Qk2: 2SC6144SG, NPN Bipolar, 50V, 10A
Qk3,4: 2N5210-ND, NPN, 50V, 100mA
Qk5: KSA1142OSTU-ND, PNP, 180V, 0.1A
Now the relay has no delay when turning on, a slight delay when turning off, and thumps through the speakers on both on and off. Two questions:
1. Did I replace these transistors with the right components?
2. Could the transistors I got be NPN when I ordered PNP? I have heard that counterfeit transistors have been known to make their way over here. How to check?
2. Is there some other component that can also fail that I have missed?
Thanks for all the help, I appreciate any input on this. I did all this work last November and haven't been able to use this since then, so I would like to get this going in the new year. Unfortunately, this also means that I don't remember if sound comes out of it.