BX1000 service manual or schematic

[andreb1160]

Hi, I'm looking for the service manual or the schematic of my BACK UPS BX1000 from APC. The unit is defective; it is always indicating an overload even if nothing is connected to it. The problem happened when I was connecting and disconnecting a PC to it. Each time I was connecting the PC the BX1000 was indicating a short overload (1sec). But one time it gets stuck and never came back from overload. Any idea of the problem?
Thanks for your help.
_________________
André

[torbjorn]

Check if there are any current measuring shunts (low ohmic resistors, probably in series with the emitter or source of switching transistors), and if any of them has changed value or got open circuit. Also, make the usual checks for shorts etc of all major power semiconductors.

[pierre canada]

check for shorts on one or more of the six transistors (POWER F.E.T.) 34N20.