Au-777d overheating/right channel distorted

Hello thanks for the advice I'll try it tonight I also noticed that noise come out from the speakers when I turn the unit on... it sounds like capacitors energizing... i' m pretty sure this is not normal.....any idea of what could be causing this? Thanks
 
Yes on cap coupled units, a thumb from the speakers is normal during turn on - also if you turn the amp off while playing you will continue to hear it play for 5 sec or more while its caps are de-energizing.
 
Hello
Well still having trouble setting bias... the meter reading keeps jumping up and down so I can't get it calibrate. Pretty sure my meter is fine.. any other way to set bias instead of connecting the wires tot he fuse holders?
 
There will often be some scooting up and down when you set bias via fuse holders - I usually let them stand for 10-15 min. However it sounds like yours is a bit more erratic - is that for both sides ? At least try both sides and if one side locks in bias smoothly you can swap driver boards and see if fault follows. On that note be A) careful removing and re-inserting the TR815's from their sleeves B) check TR815 that the 3 leads are making good connection, while the 2sc281 (TR815) transistor rarely makes trouble, its leads can dislodge if the boards have been moved around or worked on, this could certainly cause biasing issues as this transistor acts as a thermal feedback for the bias circuit.

As for alternative setting procedure, I just described that in post 20.
 
Hello. Still having erratic readings...I checked tr815 everything looks good. I am pretty sure tr 815 is working properly since I had problems before with the power outputs overheating and found out that the old 2sc281 were the problem... I started to believe the problem could be tr 805 tr 806... my amp had 2sc283 installed but they were dead anyway so I replaced them with 2sc282 that was the closest match I could find.... I also tried with 2sc 1815 but was unstable as well and the sound was horrible.... do you guys think tr 805/806 could be the issue?
 
Have you tried double-checking the erratic readings by switching the meter to mV (you may also need to change the meter lead ports) and measure for mV (not mA this time) across the large white emitter resistors?
 
Hope you finished with your issue. I just got Sansui au-777 which is quite normal. after recap, the most left transistor gets hot.

Turns out the issue was only because the C825 and C826 was installed to low, hence the plastic body touch the chassis. adjusting the capacitor ring holder and creating a space around 2mm solved the issue. it seems weird but it happens.
 
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