This was originally posted on APC forums on 8/25/2015
I came across a BP1000 with dead batteries, and missing the front panel. I installed 2 good 12vDC batteries for 24vDC, and plugged it in. Nice hum from the transformer, a single beep, a click or 2, and it sits. Its charging the batteries just fine. 118 vAC are getting to the main relay (RLY 1), but not passing to the outlets, since the unit is off. However, with no front panel, I need to know how to turn it on. The ribbin cable has 8 wires on it, although its labeled 1-10 on the main board, odd. Anyway, on the J11C socket (for the ribbin cable) I have 4.9vDC on pin 8, 4.4vDC on pin 5, and GND on pin 4. Are one of these pins listening for a low(GND) or high(~4.5vDC) signal to turn the unit on? Would it be possible to get a pinout of the ribbon cable, or a full schematic for the unit? My only other thought would be to try going in through the DB9 serial with a laptop and turn it on.
I cant seem to find any available front panels for this unit, and I wouldnt want to spend more than $10 to test it anyway.