IIRC this model and the APC badged version of it at the time, 'may' have been the same units internally
APC may have some docs kicking around for theirs,
highly doubt you'll find much if anything on the Compaq unit = been there a while back
and luckily ?! it was faulty batteries that checked ok

coupled with dodgy connections and client's dodgy+ power strip
and a blanket of dust and crust.
Does the 'patient' resemble the 'borrowed picture' below?
Good luck with the video

put me down for a looksee