Brian E. Brzezicki
Copyright 2020
Version 1.00 04/12/2020

Disclaimer
Use this at your OWN risk, do NOT sue me if it breaks your board... if your doing this your board is probably already broken though ;)

Game Board #1 04/12/2020

Problem: Game does not work, high beep then low beep in test mode, no video
Video of repair

Troubleshooting/dianosis steps:

  1. removed mathbox/aux board
  2. Hooked to jamma test bench with +5 and GND tab
  3. Fluke BUS test - OK
  4. Flue RAM LONG - 0x0000 - 0x03FF - BTS @ 0000 0x0F - that 2114 @ J2
  5. Fluke RAM long - 0x2000 - 0x27FF - OK
  6. Fluke RAM long - 0x2800 - 0x2FFF - OK
  7. Replaced J2
    • Now getting DCD @ 21F bits 5
    • tested to make sure if 21f and 23F are geting the same data when written to either, they are NOT, means it's proably a false DCD error
    • Wrote data to 21F noticed top 4 bits were not set correctly, that's 2114 @ H2, replaced
    • Now Fluke long 0x0000 - 0x03FF is OK
  8. put board back in cabinet, does not work
  9. Tested ROMs, 2 were bad, replaced
  10. Game works!