For the last 10. years I have had no trouble with my Williams Black Knight till this week when the game started crashing.
I found the problem was a bad Game Rom at IC 26 on the CPU.
Unplugged the chip from the socket and found one of the legs had broken away.
With Many thanks to Ken (Skybeaux), he sent me replacement ROM for IC 26.
All went well till I checked the other Game ROM IC 14. and found the same problem, I was real careful with lifting the chips from the socket.
So now I am waiting for a replacement for IC 14 then I will be back in action.
These chips look very cheap as the legs seem brittle if I try to bend them.