No Sound Diagnosis

Amp lights up and seems to work but there is no sound

• Look for burnt Secondary or Hi-T fuse, open the amp there may be fuses inside.

• Check Loudspeakers before turning the volume up to full - use a 9v battery across the speaker jack. Connect and disconnect the battery repeatedly and you should hear the speakers clicking as well as seeing them move. In a noisy environment put your hand on the speaker cone and feel it move

• Look for broken tubes, they will appear white instead of silver

• If there is an FX Loop plug the guitar into the loop return to see if the power amp is working.

• If there is an FX Loop remove all FX and use a guitar cable to jumper the Send to the Return. Plug the guitar into the front of the amp and test it again.

• On JCM800 amps, check for loose high input jack. This jack often shorts out against the low input jack when you try to tighten it from the exterior. Open the amp and make sure that it is not shorting.