Quoted from PinballManiac40:
Could be either. Is there any battery corrosion at all on the CPU board? If so, likely that is where the issue lies.
First try to press on all the socketed ICs on the CPU board? If it didn't help, I would swap in the MB
AV board into the SS
. No need to swap the sound ROMs between the boards. Only will have wrong sounds, which will not hurt anything.
If you want to try the CPU board, you only need to plug in the J210 power connector and the 2 ribbon cables at the top of the CPU board to test out the ColorDMD.
1) Is there any battery corrosion at all on the CPU board?
There is none present, but the battery has been replaced with a NVRAM battery eliminator. Also the ROM chip has been replaced with a KSARCADE.NET 1.5 SS chip.
I did carefully remove all removable chips, check their legs and reinserted them. Then tested with no change.
2) I then did swap in the MB AV board into the SS. No need to swap the sound ROMs between the boards. Only will have wrong sounds, which will not hurt anything. Note: In these tests all I did was turn on the machines for testing the display to see if the display worked.
The MB AV board did no change to the SS display, but also put the AV board out of the SS into the MB and it did work the display in the MB machine.
So inclusion I would assume the AV board out of the SS is in good working condition as it did work in the MB machine.
3) If you want to try the CPU board, you only need to plug in the J210 power connector and the 2 ribbon cables at the top of the CPU board to test out the ColorDMD.
I then installed the MB CPU into the SS machine and only plugged in J210 and the two ribbon cables and tested. Machine came on with normal bong and display worked! The display did come up, but with an error message of check F106 and F101 fuses. I did check these fuses and they are in working condition. The machine did have an error message before with the original SS CPU in as the machine did dong, dong, dong after the initial one dong once its turned on (error message), just did not know what as I could not see this due to the non-working display.
Okay, the display problem appears to be with the main CPU board that has an issue, but what to check for next? Traces appear okay and have beeped them out with my meter as best I can. Also is there an second issue with the driver board with these fuses or is this just because not all connectors installed when I tested the MB CPU board in the SS machine? Not sure because the machine had this issue before I traded the SS CPU for the MB CPU.
Final note: Machine does play a game and appears to have no other problems other than some minor switches that need to be adjusted and/or replaced.
Any additional help would be appreciated.