Thank you Nomad. A friend hooked up one backwards to a lot of juice apparently and there was no fuse inline ? (or so he says) well , my knowledge of amps is far and in between , This was just a run of the mill Chinese made Blackcat 300HD , I opened it up and the main diode and a 220uf cap were exploded !! everything else looked fairly clean (I know , looked doesn't always cut it) I changed the cap and the monster diode , The amp fired up , I put 2 watts in to it and nothing , no power out ,not even the 2 watts I was putting through it , The receive amp did work ,but IM guessing that has nothing to do with the transistors ? and the little relays were clicking off and on when keyed.When i shut the amp off ,I got my 2 watts back from the radio. This is really poking and hoping for me here Nomad ,I have changed transistors before in amps with success ,but IM just not sure enough with this one ? Getting the 2 new transistors is not a problem , it's just the fear of wasting my time and money here,it looks (IM not real sure) like the board is double sided, and it looks like the only way to get the board out of the heat sink is to remove the transistors in the first place )-: if the cap and diode were distoryed , IM now thinking if the board is double sided there could be some damaged traces on the bottom ? Looks like there's more exploratory that needs to be done , or just can the thing. Thanks again Nomad.