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Sansui au-888 transistor replacement issue

Chriswashere

Chriswashere

Active Member
Hello all. I have a Sansui au-888 with the famous "crackling transistor issue". This should have not been a big deal. Just pull the "flying saucer" transistors out, then install the new ones. However, after doing this, the amp started to smoke despite all transistors being installed correctly. Worse of all, the smoking channel is the channel that never had any issues. Smoke started around 50v AC through the variac give or take.

I replaced the 8002 transistors with Bc639 transistors, which I read somewhere were replacements. Any ideas on this one? Pinouts were checked as well.
 

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Where did the smoke come from? How many transistors did you change on that board? Some are PNP. Check for short from solder.

Rob
 
Did you check the pinout with a meter, or just reading the datasheet?

Also, some new part can be bad, it happens. I"d check the soldering, the pinout with a meter, and check for a shorted transistor.
 
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