Quoted from mjalexan:I'm working on a Tri Zone that was booting and playing properly. After adding a socketed NVRAM (weebly) and replacing C23, the game would be stuck in Audit mode. I could cycle through the audits but never get out.
<Fast forward through all the installed MPU troubleshooting>
The MPU is out and separated from the PSU. Leon's test ROM installed, 5V power supply, reset circuit jumpered, game ROMs removed.
Upon power up, the two LEDs blink continuously....good
After pressing the diagnostic button, 1 flash, both LEDs stay on, indicating IC19 (new NVRAM) has failed.
While the two LEDs are both still lit.....
Scope is out, NVRAM has activity on all the data and address pins measured at the chip.
scope pictures attached for CE1, CE2, and OD.
is CE1 going low long enough to enable output?
Same setup, there is no activity on pins 18 (A9) and 25 (A15) on the 6808. However, when i press the diagnostic button again, there is activity on both pins temporarily, then they drop to 0 as both LEDs stay lit.
Do either of these throw up a red flag? Any other suggestions?
I've used a second NVRAM and two original 5101, same result. I've re-socketed IC17 and re-resocketed IC19, both appear to be correct.
Thanks for any input.[quoted image][quoted image][quoted image][quoted image][quoted image]
Have a Williams Blackout that when purchased was already socketed at the 5101 location.
Popped in a new Pintech NVRAM module and it went into audit hell just as you describe, nothing I did would get it out. Ended up reinstalling the 5101 ram and batteries and all works as it should. Door switch open/open, open/closed, closed/closed made no difference. The same NVRAM module went into a Gottlieb System 80 Alien Star and works perfect.
Would be very curious as to what you find as I hate batteries.
Bay Shore, NY
