depth finder repair

I have a Pinpoint 7520 depth finder that needs some repair. Does anyone know a good place to send it? When you turn the unit on, the backlight flashes a few times then there’s a beep and the unit shuts itself off. I pluged my 7420 depth finder in and it works fine so I know its the unit and not the connections or any thing else. I live in Carroll County IL (NW IL) if there happens to be a place close.