White screen after Ram Clear

[jthelman]

I bought this machine as is, not knowing what issues it had. Got it home and replaced the dead battery. I started up the machine and the MPU board lights started flickering off and on causing the monitor to also flicker off and on. So, I then did a clear ram using a key 22 chip. After clearing the ram, the machine booted up but having a “door open B” error. I checked the bill validator door wires, and they are tied together and checked continuity back to the backplane board and it was good. Thinking about the MPU board is bad. I purchased 3902 MPU board, swapped out the 3803 rev A board to a 3902 board but it also had a dead battery that I changed out. The machine booted up “Hooray” but would not accept any coins. I pressed the white test button on the comparator and displayed “Coin Jam” or something like that. I cleaned the coin comparator and coin optics. Error would not clear, so I decided to do a ram clear with key 22. Went through the clear ram process okay, put the base chip back in and I just get a white screen. I tried clearing the ram 5 or 6 times with no luck. I also tried the 3803 MPU board, it also just has a white screen. Hopefully, someone can help to get this machine to boot back up.

[rickhunter]

If you can perform a clear, but then populating the machine with the game eproms results in the machine not coming up, then I would suspect the base chip.  If you at any time plugged it backwards, you may have fried it.  Also verify all pins are good, etc.  What do the LEDS on the MPU look like when you have the non-booting condition?

[jthelman]

Strange, after 2 days and several clear ram tries. I inserted the MPU tray back into the machine and it booted up with several errors “see picture.” The screen then initialized and produced calibrate touch screen and to touch the dot on the screen, but I did not see the dot. I could not get out of the calibration screen, tried turning off the machine, reset key and MPU test button. I then did another clear ram and now getting the white blank screen.
There are 4 yellow LEDs lit up and I don’t believe I put the chip in backwards?

[rickhunter]

You have the older style cabinet that was meant for 380x boards.  I'm not familiar with troubleshooting for those since they didn't use the newer style I/O cards.  The touchscreen errors can be linked to a netplex issue or a bad touchscreen controller/screen or some other netplex device causing the failure since they are all in the same bus.  Since you did a clear and have not setup any of the settings, you are getting the Accounting Denom not set issue and the options verification issue.  When you do a clear, you also need to do the keychip option so you can setup denomination and other protected settings.