I'm currently testing a spare Williams System 6 MPU and Driver that I have around. Both boards look clean, and I believe have had some decent work done on them in the past (ROM sockets newer, other chips socketed, headers reflowed, etc.)

Currently when it's hooked up it seems to be trying to boot, but gets hung up or glitches. Sometimes when I turn it on, all the displays just show steady zeros on every display position. If I turn the game on/off (coin door open) it will either keep doing the same thing (all zeros) or the displays will go dark and nothing happens (no boot). Sometimes the displays get really dim when I do this, but still show all zeros. On rare occasions, the displays will show a little garbage/mixed digits before going all zeros as well.

Just curious if anyone has ever run into this issue. I did a little searching, didn't see this exact description.

Hmm could be. The guy who gave me the boards said they came from his Firepower (made sense, the MPU had Firepower ROMs). He was experiencing minor issues, things that either sounded driver board related, or perhaps not even board related at all. Some lights out, a flipper being weak, a pop not always firing, etc. He wasn't a technical guy, so he called a repair person who swapped out both of his boards for a new combo board. When I picked up a totally unrelated game from him, he handed me these boards along with that information.

I'll snap a pic or two of the boards and add them. Is it possible that they don't work in the game I'm trying them in? I have a Tri Zone. I picked up a new set of ROMs, the game ROM and two green flipper ROMs. I placed them in the lower row on the board, and removed the three chips that were above it previously with the Firepower setup. Not sure if there's more I would need to do. I know some of the pictures I found of the TriZone boards on Pinside were a different configuration system 6, but I assume they were cross compatible?

Edit: By the way, I didn't hook up all the solenoid connectors when testing. I was primarily just seeing if it booted, and did not want to worry about bad transistors or anything (though I did test those on-board and they seemed ok).

FP_Trizone_Conversion - Copy (resized).jpg

PINTEC Sorry for the delay, here you go. Please let me know if you'd like any additional pics, happy to take whatever. Thank you!

FP_Trizone_Conversion_back - Copy (resized).jpg

FP_Trizone_Conversion_chip1 - Copy (resized).jpg

FP_Trizone_Conversion_chip2 - Copy (resized).jpg

Still no luck after a reflow. Since I don't need the board at the moment, I'm going to put it in the check out later pile when I have time. Thank you all for the help. If I take it out to use it in the future, I'll circle back to this thread