The low battery indicator was illuminated on the ESonic2 HD control panel on my DR-500MCE. So I changed the batteries (two AAAs, contrary to what the online manual states), and now I get nothing. None of the LEDs light up, no sound when connecting to an amp. I switched back to the original batteries as an experiment, still nothing. Tried positive up, positive down. It's as if there is no longer an electrical connection. Note: after removing and putting back on the sliding cover for about the fifth time, the copper plate fell off. It snaps back on just fine, though, and is secure. Has anyone else experience this?