texasmame
Well-known member
No RAM/ROM errors on self-test. No mathbox or matrix errors, either.
Can start game normally and everything works except there are no TIE fighters, Death Star nor stars. You eventually do get to the DS surface, but all towers come up in a straight line at the center top of the screen and you can't quite reach them to shoot any of the tops. Eventually you die.
As most fixes for this problem point to them, I've cleaned the existing Instruction PROM set and even replaced those sockets. No change.
All voltages good (+5V at least 5.09 throughout both boards) and the rest are all in spec, too. Math box RAMs (5F and 5H) cleaned and swapped to no change. All EPROMS check good via checksum.
Also, per the troubleshooting PDF, I confirmed the 3mHz clock was present in the pseudorandom number generator (4D, 5B, 5C, 5D) and that PRNGCLR was high during gameplay.
Have a new set of PROMs coming from Hobbyroms. Anything else to check in the meantime in case it is not the PROMs?
Can start game normally and everything works except there are no TIE fighters, Death Star nor stars. You eventually do get to the DS surface, but all towers come up in a straight line at the center top of the screen and you can't quite reach them to shoot any of the tops. Eventually you die.
As most fixes for this problem point to them, I've cleaned the existing Instruction PROM set and even replaced those sockets. No change.
All voltages good (+5V at least 5.09 throughout both boards) and the rest are all in spec, too. Math box RAMs (5F and 5H) cleaned and swapped to no change. All EPROMS check good via checksum.
Also, per the troubleshooting PDF, I confirmed the 3mHz clock was present in the pseudorandom number generator (4D, 5B, 5C, 5D) and that PRNGCLR was high during gameplay.
Star Wars Troubleshooting Guide
falz.net
Have a new set of PROMs coming from Hobbyroms. Anything else to check in the meantime in case it is not the PROMs?
