What could be causing my Fender Blues Deville Combo to be barely producing any sound?

For a while it was still producing sound jut very quiet. Like id turn the master all the way up and it'd sound REALLY good but really quiet for the level the volume was at. In fact it even sounded better for a while because I could get the power tubes real hot. It was really nice sounding actually. But there was also this annoying little squeak/squeal sound whenever no notes were being played on the guitar.

Now it is even quieter and barely able to be heard above the strings on the guitar.

Any idea what could cause this?