sw 3048e dead

hi guys
looking for advice
just done some routine battery maint today and disconected inverter.
but when i re applied power all i got was all the lights flashing on the input keypad and no display
all input voltages ok
been looking all over for for some technical info on this inverter schematics etc but have drawn a blank
anyone know where i can find these

and also any one know what the difference is on the control board between the 24v and 48v versions
i have an old 24v version that the transformer melted in a few years ago
and with no info and nothing to loose i changed the eproms and put the 24v board into the 48v inverter
this worked to a certain extent as it comes on and inverts fine all outputs correct so i have power again phew
however the voltage displays are incorrect as it shows battery voltage of 71v with a 48v input
and it wont charge the batterys when i fire up the genny i guess it thinks 71 v is enough.

done a quick visual and a tour round all the easy to test components on the control board from the 48v inverter and found 1 diode short d19
if anyone knows what this does as i dont but looks like it is connected to t1
will change it tom and see what happens when i put it back in could it be that simple will post with update

but really could do with a schematic
thanks for reading the post