Korg TR-88 has gone mute

[MontyS88]

My Korg TR-88 isn't making any sound at all. I've tried the headphone jack, a mixing board and a keyboard amp, but I think it's the actual keyboard that isn't producing sound. It also won't respond to MIDI commands via USB.

It was working fine Thursday night, and all it did between then and Friday night was sit in my room. I got home and turned it on, and the sound wasn't working.

Any suggestions on what I could do to fix it? We're kind of in the middle of recording a demo here, and we REALLY need a keyboard to do it with.