ToneMaster Not Coming Out of Standby?

[Chris Bauer]

I've been using a ToneMaster Twin around town and it has now on three occasions refused to come out of standby at gigs. (Luckily there was a house amp available each time.)The first time, I brought it home and it worked fine. The second time, needed or not, I updated the firmware and it worked fine for a few months. Then, it did the same thing again a few days ago. Once again I brought it home and it worked fine.

It's not the dreaded power diode issue because it powers up fine almost all the time. Power in many of the places I play is notoriously bad but I couldn't replicate the problem using a variac and feeding it too little or too much power.

Could it be as simple as a bad standby switch? (Not that I have the skills to check that..)If so, it seems odd that this issue has only happened away from the house. Anyone else having this problem or heard of it? Possible fixes?

[Dave Grafe]

Possibly a bad switch, more likely a bad solder joint or cracked trace as I believe the switch is mounted on a PCB sub-assembly. If at any time the nut that secures the switch to the front panel becomes loose the mechanical stress induced when the switch is toggled is passed to the PCB traces instead of the front panel. The same can happen if front panel alignment is poor or if too much torque is applied at assembly, in either case the failure can be intermittent.

[Chris Bauer]

Hmmmm…. With a PCB amp, are those tough to figure out/fix or would either of those relegate this to the junk pile due to a lack of reliability?

[Dave Grafe]

Shouldn't be too hard to track down, there are YouTube clips that show how they are put together. If you have decent soldering skills it's a matter of re-flowing the traces with a touch of fresh solder and making certain all front panel nuts are secure.