I think something's wrong with my APS..

I plugged in a 2400 pack to charge, came back 15 mins later and it was displaying "Low Voltage". I have a 20A PS, so it couldn't have been that..

I shut it down, tried charging again, and it said "Check connection".. opened'er up, the 20A fuse blew.. strange..

I replaced it, and tried a motor test. As soon as it give it a bit of voltage, the power supply light starts dimming, I hear a low squeal coming from the APS I think, and it stops, saying low voltage. I haven't tried another battery pack yet, but I can imagine it just might blow a fuse again. The 15A fuse looks fine.

I have a second APS, hooked it up and it works fine with the motor run, so it can't be my power supply.

Time to send it in for repairs?