Hi all. I have an M4 power amp with a major problem. Right ch. output heatsink gets super hot while the left one stays room temp. So I'm thinking Output transistor short. But before any disassembly to indentify the types of output trans. visualy, I would see if anyone here can tell me what their type #s are. 4 per ch. And even if they are still available or good substitutes. Any info is welcome and appreciated. Thanks.