70s fender amp reverb not working

This can be a common problem on Fender amps.

Are you sure? Google is your friend. It may take some time, but if the problem occurred randomly at once (not intermittently) and the amp is not physically damaged, the fix should be easy.

yes. I think it could be the power tubes (6L6GC) because sometimes the audio drops out.

im going to do some more research. 

is there a way to tell if tubes are bad by looking at them?

If you have to guess if the power tubes are bad, just get new power tubes and go from there.

@hotei yeah, I need new power tubes. Now there is no output at all. But i didnt know that 6L6GCs were that expensive.

Try 5881 as an alternative, maybe more luck in cost.