The circuit board consists of two main parts - motor drivers and computer interface circuitry.
A quick blast of the air duster removed 30 years of dust from the board... Must actually remember next time not to do that inside the house !
The large edge connection shown in the picture above is where the hand controller connects. This is not the same interface where the computer would be connected.
A couple of heat sinks were loose, so I pulled these off, and will remount them later with suitable thermal adhesive.
On the surface, nothing really alarming to be seen here...
Final thoughts for the day : I'm somewhat concerned about this interface board, the hand controller connects directly to the driver board which means none of this circuit board has been tested by myself. I actually have no idea if the electronics work or not! I'm going to put the base back together for now, and continue sorting out mechanical problems first. The track can in theory be repaired, luckily this is 1980's technology after all - not your modern multi-layer boards with microscopic SMD componentry, making servicing virtually impossible!