SWR WorkingPro 400 distorting

[jp3zone]

Hi guys, was wondering if anyone could help me with some advise and the schematics for a the SWR Workingpro 400 head. Can seem to find the schematic anywhere .

The speaker output is distorted, but signal form fx send is fine. Injected signal into fx return also distorts, sounds like broken connection.

So leeds me to a faulty PA?

[Jazz P Bass]

Contact Fender for the schematic.

[Jazz P Bass]

Here is the schematic.

WorkingPro 400 & 700 schematic.pdf