I believe there are 2 slam tilt switches on FP, one on the coin door and one under the Playfield. Do not set these too tight, in fact, in home use, they can be gapped at least 1/4 inch apart since you should not be beating on your machines like machines sometimes are in a bar. These switches are there to protect the machine from abuse in the wild. If these are gapped too tightly, they can close during normal play and end your game.

Hard to diagnose via the internet, unfortunately. Could be that something is triggering the slam tilt, could also be the 40-pin interconnect is going bonkers as it heats up.

Are your coin switches grounding against the frame at all?
Any other oddball behavior going on at the same time the game is resetting?

how are the bridge rectifiers? i just had all sorts of trouble with a firepower here that turned out to be a BR shorting to the top/heatsink and messing up the ground ( 19v between playfield ground and backpanel ground really upsets the mpu)

my black knight does the same exact thing, which is the same as firepower . I don't mine is mpu related because I have the rottendog board in it. someone mentioned power supply board to me once, haven't had time to check into that one but just a thought.

If the pin tilted wouldn't the "tilt" light up rather than "game over"?

Put some tape or shrink tubing over the tilt contacts to make sure they do not touch. This will eliminate them from the possible issues.

Not if it was a slam tilt. It would just reset back to attract mode.

Slam tilt is pretty harsh on these games, it actually re-sets the CPU completely.... same as if you power cycled the game.

-Hans

The plumb bob tilt, ball roll tilt, and slam tilt switch on the coin door are all located in column 1 of the switch matrix. The playfield tilt is located in column 6. You can try to eliminate the first three as a possibility by removing the plumb bob and ball roll, and disconnecting the door harness then start a game. If it still tilts then you know those three are not the culprit. If it doesn't, then you know you have to look at one of those.

You can also go into test mode as soon as it resets and look at which switches are reporting as closed. This is best done with the glass off so that as soon as it resets, you can grab the ball so it doesn't activate any more switches. Of course the coin door harness will need to be hooked up for you to do this.

If it still resets with the three tilts disconnected and you're sure it's not the playfield tilt, you have to look at all the typical Sys6 issues (power/connectors/ROMs/ROM sockets/40 pin).

viperrwk

Dont rule out the big connector even if it has been replaced. there's at least 120 to 160 connections there when you factor in board to male pin, male pin to female connector, female to board etc. A lot of hackers out there...

Hey @njpinwiz, if you are still around, I am wondering if your new CPU solved the issue for good? I am having the *exact* same problem. I have gapped the door slam tilt, but not the playfield one yet. Bu I don't think that's the issue, since it sometimes happen during a rollover when the machine is barely being touched.

Did the Rottendog solve it?

You may benefit from a thorough test of your CPU board. I've just released a diagnostic adapter that comea preloaded with these diagnostic ROM images:

http://pincoder.ca

Download the release version from them menu and checkout the .txt files for each test. If you want to try them on your board you can get the adapter here:

https://pincoder.ca/index.php/2020/07/10/adapter-2020-06-23-0506/

Or, if you have a chip programmer and the proper chips you can write the images in the zip file to your chips and run them.