Thank you Chris, yes, they seem to be very scarce.
My Golden rule is to always check voltage supplies first so I agree.
The Eproms papers did just fall off before I took the picture, ( Actually blew off with the wind ) but are covered again.
No Reset buttons on any boards, only the side key that I believe is used in a reset procedure.
The OA2 board is 1990 but unfortunately, the plate on the right hand side has been removed so there is no actual model number, etc
Possibly done when they took these out of service.
As the CRT displays correctly at boot, no CRT problems I can think of.
I am guessing with so much down time and no battery, the first thing will be a battery followed by clearing chips as that seems to be the common theme
but as there seems to be very little machines in circulation, it limits the amount of data available.
I have only had it 1 week so still yet to go into it deeply. My concern was a corrupted MCU or bad eprom would render it useless. Anything else, I can repair.
Thanks again !