Fishman preamp problem

[123john]

The preamp unit in my Yairi DY 45 is not doing much. This is a link to the unit:
http://www.fishman.com/products/view/presys-oem-1
Let me start by saying that I have never had a preamp before so I am not familiar with their operation. I assume the unit comes on when you plug a cord into the output jack, but please correct me if I am wrong on this.
I put a fresh battery in it and the only sign of life is a regular flashing of the top green segment around the tuner display...that happens when you push the tuner button in. Otherwise, nothing happens, and nothing comes out of the amp. Is the red battery light supposed to be on when you plug a cord in the output jack?
I would appreciate any troubleshooting suggestions, thanks!

[GmanJeff]

The user guide on the Fishman product page you cite indicates that you're supposed to get a single flash of the battery light when the guitar is plugged in, to indicate the preamp is on. Since you don't say you're seeing that, I'd conclude the preamp is in fact not being activated when you plug in the guitar.

You might have a problem with your input jack not completing the circuit when a plug is inserted, there could be a wiring issue between the jack and the preamp, or the preamp may have a defect.

Fishman's customer service is good - you might contact them for guidance with regard to the meaning of the flashing green light segment you mention, as that might be a fault indicator.

[123john]

Thanks, Jeff, you have given me lots of things to try. Hopefully one of them will work out for me. I don't play amplified, but since it's there I would like to try to revive it.