Audio Systems: IC on Fisher Studio Standard Amp burns out, fisher studio, speaker wires

Question
Hello:
I have a Fisher Studio Standard rack system that's about 29 years old. There were some problems with audio cutting in and out so I took the amp (CA-800) it to a local repair shop. The tech cleaned oxidation from the unit. Brought it home, hooked it up, played one side of an LP and there was a "pop" sound on the right channel. No sound on that side after that. Took it back and was told that the IC chip on that channel had burned out. The tech replace it--I brought the unit home again and hooked up the speakers incorrectly (arrgh!), and burned out the IC again! I took speakers back with the amp to the tech. Again, he replaced the IC, tested the speakers (ran them on another amp) and ran the repaired amp with my speakers for two days. Everything was working fine. I brought everything home--was very careful to hook everything up correctly. Sounded wonderful. I played several CDs and LPs and everything worked great--but the right channel popped again! Volume was moderately high at the time, but I wasn't trying to "blow out any windows" if you know what I mean. I assume that the IC is again burned out (STK-0080A, as listed on the bill). The left channel is just fine. Just the right side. I didn't take my speaker wires to be tested--but it seems unlikely that the right wire would be a problem as it worked fine before the cleaning and repair. Can I replace this IC myself? (Does it plug in to the heat sink? Or is it soldered?) What else is going on here?
Many thanks for any help that you can offer.

Answer
The STK-0080A integrated package is good for 80w of audio power.  It dissipated alot of heat since it is a class AB configuration and must be very carefully heat sinked.  The problem you are facing - assuming you are not shorting the wires at the output of the amp or at the speakers - and you can check that by just swapping the wires from left to right and right to left and see if the left channel blows! - is the heat grease and mounting of the IC onto the metal heat radiator.  The heat transfer grease must be applied very carefully and thoroughly and then fastened correctly such as to allow for the correct flow of heat.  If the heat transfer is not sufficient the STK-0080A  will become excessively hot and break down.  You can check this by comparing the temperature of the IC to the other channel.  If the right channel is running much hotter than the left channel it has a problem somewhere.

Replacing the IC on your own is ok assuming you know how to desolder and remove the old one and install the new one correctly as outlined above.

That is my opinion. Hope you get a happy solution.