Well ..... long time ago it seems, I made this post and never closed it.
FUN FACT: I know a guy who repaired me Peavey Bass Amp, and I gave him the non-smoked module I had to see if he could resurrect it.
He tested everything he could ... but stopped short at the IC , which he said is propriatary GM.
Diodes - good
Caps - good
Diodes - good
The chip he recognizes, but has nothing specitic about it and Google is keeping any info on it close to the vest tool
If he knew what numbers GM removed and then stamped their own ID on it... he would have no qualms.
Maybe -------> someone knows the generic IC number? Mebbee?