"Jeroni Paul" wrote in message
ups.com...
Are there any fuses on the board?
Most UPS have a fuse for AC input, another for the output and another
for battery, check all them.
The battery one might look like the fuses found in cars. Otherwise you
will have to troubleshoot and see where the current gets or doesn't
get. Keep an eye that if the battery fuse is gone there might be
something else wrong like shorted transistors, etc. I would try to
supply with a 12V current limited source after replacing the fuse.

The battery fuse is an inline fuse between the 2 batteries (its a 24V
inverter) this is visibly intact and I checked the 24V is getting to the
transistors, the mains fuse is a button type circuit breaker and I checked
240V is reaching the board, can't see any other fuses but it isn't easy to
lift the board out because of the heavy cables to the heatsinks and a very
fragile flexiprint to the front panel.