Orion HP-4800 help

Hi everyone


Trying to troubleshoot my Orion HP 4800. It powers on and works however the rear ch3/4 speaker output is very low. Gain has to be turned up almost all the way and even then it is very hushed. I assume it is some sort of fault.

When connecting the 3/4 channel to 1/2 channel, speakers play nice and loud. Seems that the 3/4 channel output has some fault

ESP light is constantly on.

Any advice would be appreciated.
 
I can hear some sound, but it is very hushed compared to the front 1/2 channel. I would say 30% or less comparatively speaking. plus distortion.

If i connect the 3/4 channel (rear) speakers to the 1/2 channel they play loud and crisp.
 
I would say its minimal distortion as compared to the fact that it is very hushed. As i turn the gain up i hear some crackling, but not much.
I do not have a scope, I have taken the amp off and removed the back panel and taken the board out to inspect. No apparent burn mark or apparent solder issues that I can see with my untrained eyes.