Quoted from Theonlylilo:Good morning to all! That’s the situation, and is not the first time that happens to me..
I‘m working on a Trizone cpu board with a fault on the cmos ram 5101. Once replaced, the board passes the test bench with the usual Leon test rom, but with the game roms installed and pressing the diag. pushbutton (after the correct flashing), the upper LED remains lit. From manuals seems to be an error occurring on the game romset (especially on IC14), but changing them with a known functioning one the problem remains.
The board works on the pinball, but I wouldn’t like “this problem” could cause me other problems in the future.
The board has new sockets, new game romset (burnt on a 2516 eeprom), new interboard connector, new 5101, only a 6810 on IC16 (I use the internal ram of 6802 cpu), AMI 6821 PIA on IC18.
Where I can crash my head?
A great place to go next is here: http://pincoder.reversion.ca and try each of the test ROMs there. Start with 01-bus and work your way to 13-sounds. The ram and CMOS tests are more reliable than the built-in tests as they test every location with every possible data combination. They should help in finding the issues.
The official thread on these ROMs is here: https://pinside.com/pinball/forum/topic/new-williams-system-6-in-game-test-roms/page/2#post-4622675
Bay Shore, NY
