Quoted from westofrome:

Brought home a Meteor and all is working except the sounds - which were working at the machine’s previous home.
Adjusting the volume knob at the bottom of the cab is not producing any white noise, so it seems like the amp is the issue.
I am getting no vdc at TP2 (should be 11.9) but am getting 5vdc at TP4.
I checked and reseated all connectors on the sound board and the MPU ribbon cable connections, and checked all fuses on the rectifier board.
Can you help me diagnose the issue?
How can I determine if it's a capacitor issue or something else, like a connection?