wiring of Sportrak Map

I have been given an old Sportrak Map which has started acting funny,
and I am trying to revive it (currently by attempting to clean
connectors, buttons etc).

I noticed that two of the wires from the rear connectors (orange and
yellow) are not connected to their places on the mainboard (next to
black and red I presume). I don't think these are important except if
one plans to use the PC connector, though
Does anyone have a wiring diagram for the internals so that I can where
these do belong?

The unit turns on when the power button is pressed, then beeps and keeps
resetting. Has anyone seen this before and may have a tip what else
could be wrong with i?

Also, is there a pointer to any user manuals/service manual etc?

Thanks