Reminds me of a FISHER rack system amplifier with STK-0080 chips. Had a shorted Left when i got it, and i put in a new chip. A couple months later, while rocking the house, the left chip let go and smoke rolled out of the left speaker. Turns out, the bias resistor (white square 3 leads near the chip) was out of whack and it led to the demise of the new chip. Be sure to test them to make sure the prior shorted chip didnt effect the resistor..
SR