Peter - Just to confirm - you removed the MDB (with the fault) to the TW - and it works fine ?
This sounds like it is a display (P1 or P2) OR the cable TO P1/P2.
Try this ;
Place the original MDBs in their respective games. We should have a working MDB in TW, and the assumed faulty one in Gorgar.
With Gorgar OFF, remove the P1 and P2 displays. Switch it on. The CREDIT display should be fine.
Switch off. Now connect P1 ONLY - does it work ?
Switch off - disconnect P1 and connect P2.Switch on - Report back.
I think that it is a cable issue at this point.
