Pioneer SA-9100 Protection Circuit

Charsbass

New Member
I have a newly acquired Pioneer SA-9100 with the protection mode cycling issue. I've read all (or the ones I could find) of the threads on the fixes and have done them as documented but am still having the problem. The protect mode cycles every 2 - 3 seconds on and off as soon as the amp is powered up.

So far I have re-capped the power supply board - AWR-032 and the protection board AWR-025. I've also replaced on the protection board:
Q6 with KSC2323YTA
Q7 with KSC2690AYS
Added a 1n4004 diode across pins 9 & 10

Measured voltages are:

AWM-025C
Pin 1 Fluctuating too much to get a good reading
Pin 2 -13.63v
Pin 3 Fluctuating too much to get a good reading
Pin 4 0
Pin 5 Fluctuating too much to get a good reading
Pin 6 Fluctuating too much to get a good reading
Pin 7 Fluctuating too much to get a good reading
Pin 8 Fluctuating too much to get a good reading
Pin 9 30.2v
Pin 10 42.8v
Pin 11 41.9 V
Pin 12 7.53v AC

AWR-032
Pin 1 -13mv - +90mv fluctuating
Pin 2 -19.2v
Pin 3 -30.3v
Pin 4 - 13.6v
Pin 5 -52.5v
Pin 6 -60.6v
Pin 7 59.2v
Pin 8 52.5v
Pin 9 43.3v
Pin 10 30.25v
Pin 11 19.7v

Any suggestions as where to check next would be much appreciated.
 
Last edited:
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