Sola 620RM 2000VA Service data

[RJFreeman]

I have a couple of Sola 620RM 2000VA UPSes
they both generate 240V from teh battery pack when I press the On button but then shut down as soon as I release it.
while I have had a quick prod around and seem to be getting 5V on the CPU/controller card etc and power capacitors seem to be ok, charger is charging the battery pack ok, however with a 100V DC battery pack I am reluctant to prod around too much further without a service manual/schematic.

So long shot I know, but does anyone have any service information for one of these?