Horner B2A Active Electronics not working

[Patty Clam]

Got a Hohner B2A Bass, no idea when it was made. The active electronics are not working, passive mode is fine, any suggestions? And yes I cleaned the terminals and installed a fresh battery. Also, what the heck is the silver thing in the battery compartment? L-H, OUT- what does that mean, what does it do? Is there an owners manual available for this instrument. No info is available on Hohner website : (

 

[bgmww]

It's Hohner Most likely built in Korea.
The silver thing you mentioned must contain the circuit. The L - W Output is a trim pot. You lower or raise the overall level of the circuit IIRC.
I bet it's just a lose wire.