amp internals

how do u tell if an amps internal components are working/not working by looking inside? is it ok to look inside when its (amp) on?

if you see a lot of black (where it looks like there was a fire), it's not working right

and no don't do it while the amp is on

Turn the amp off, get a multimeter, And you see a lot of output transistors around the edges, that are screwed to the metal, right? Turn your multimeter to Diode test, and probe end to end, middle to left, and middle to right on each transistor, if the multimeter indicates 000 resistance, or very very close, lets say somewhere between 000, and 010, and it just stays there, that transistor needs to be desoldered, and checked again, if you get the same reading with the transistor out, on any of the 3 tests you do on it, go on the net, order a new one, and replace it. Does that make any sense? Usually these transistors get really hot, and "short out". Another test your could try, if you didnt follow me on the 1st one is, Turn the amp on for a few mins, and then feel with your hands all the transistors, Are any extremely hot after a few minutes? If so, something is causing it to get hot, it could be shorted itself, or something else may be shorted. I hope I havn't confused you guy's, good luck.

sometime u are not able to see what's wrong. for instance, my DEI amp (newer version which i don't like compared to my older DEI) has a power supply and transistor problem. I was not able to detect it, but i had sent it to my friend to check with me. Since i did not have an oscilliscope, i could not check to see what's wrong. After he checked it out, he found out that my amp is pulling current even when it is not on. The current is being soaked into the ground and the power supply is crapped. The PS does not want to work i guess. haha