advent 300 receiver

Hello, I’m an extreme novice in audio restoration and need some advice - usually get by with schematics and posts on this forum. I bought an ADVENT 300 amplifier, but is not working at all. I found some concerning things on the tuner board and took some pictures - I have no idea what this is...

I connected a single speaker rated at 36W max to one channel of an Advent 300 receiver. As soon as the volume was up to 11 O'Clock, clipping started and the receiver blew a fuse. I replaced the fuse and hooked the Advent 300 to Advent speakers (OLA) and there were no problems even up to 1...

I was given an Advent 300 receiver that powered on, and the power lamp glowed, but gave no audio. That's because the pre and main jumpers were missing. I'm using RCA cables for now as jumpers. So the receiver is working great but the power lamp is out. I have no idea what lamp is used or where...