Hugo,
on that cs800, I replaced a couple of wirewound resitors that looked burned out at the connections, after pulling them off the board i tested them and they where bad, I then ran it through it's course, it seemed to work fine. I got a smoth sinewave at the output. but the ddt never lit up, is that normal for this unit. I'm going to have to look at it a bit more, I'm not much on pa amps, mostly I work on guitar amps.
Thanks
Tony