Problem with Genz Benz GBE 750

[bjm]

I have this GBE 750 with a problem for which I seek some advice. I don't have a schematic.

The amp sounds fine when the LF Boost is engaged, but when disengaged, I hear a weak sound upon the initial string attack which then decays to a point, then abruptly goes silent (even though the string continues to vibrate). It's as if a cap is discharging into a diode, goes below a threshold, then goes silent.

I've tried some basic inspection: engaged the LF Boost switch to hear the relay click (check), wiggled and reseated various connectors (check), flexed the PCB in the area (check), mechanically wiggled or flexed some nearby components like caps, relays, switch housing, etc. I sprayed some cleaner into relays and switch. No other knobs or switches seem to have any unexpected behavior.

With all this, I have no additional clue or change in behavior. It seems clear that the problem lies somewhere in the low voltage PCB attached to the front panel.

Any ideas? Maybe someone has a schematic that might shed light on this issue?

Thanks,
-jeff

 

[agedhorse]

Your amp can be serviced under the factory service program, but cleaning up the mess after the repair attempt will add to the cost of the repair.

Message me and I will get you info on the factory service program.

 

[Jeff Genzler]

You'll be in good hands with Andy repairing it for you.

 

[Al Kraft]

This is one offer I would not turn down.

 

[ezstep]

Very likely my favorite amp. Agedhorse is the real deal - he has repaired my Genz Benz. Don't hesitate.