The issues with my Foo Fighters appear to be resolved so I thought I'd update this thread, may help someone in the future.
As mentioned above my Foo Fighters suddenly started Slam tilting one day back in March ( the day of my league meet!

). The next day and for a few weeks it was fine then it went downhill rapidly. Basically when playing the insert lamps would freeze and switches would stop registering. I could still flip the ball around but nothing registered then after a few seconds the lamps and switches would come back. Sometimes the sound would start playing up. The stuff on the display always worked fine.
Node bus test showing node bus intermittently failing then recovering....
I contacted Phil who put me onto Stern Tech support so followed their instructions going forward. Kyle at Stern was superb, pretty responsive ( bar for the time difference ) and he assured me they would send me whatever parts were required once we had got to the bottom of the issue. Luckily I have plenty of other sterns here so swapping boards not an issue for me but not sure how that would go if this was a 1 stern house. Anyway, things we tried that didn't fix the issue....
Disconnect shaker motor, speaker lights and led strip I'd fitted
New SD card
Swap out each of the machines network cables, one at a time
Disconnect QR reader
Disconnect serial connections that go to lamp boards ( CN2 on node 8 and 9 )
Disconnect serial connector that goes to trough opto board ( CN3 node 8 )
Swap CPU with another machine
Swap cabinet node board with another machine
And finally....
Swap node board 8 with another machine.
This seems to have fixed the issues








I've had maybe 2 dozen games with no problems. I've swapped back in the suspect node board and issues returned, and I've now fitted a new board that stern sent me.
The LED's on node 8 and all the other node boards including the CPU never showed there was an issue and even in the node test the whole node bus was brought down, not just node 8 so there literally was no way to know which was the faulty board, bar for swapping boards out until the faulty one was found. Stern say they've never seen this issue before ( hence the weeks of back and forth with them trying each suggestion )
My fingers are firmly crossed.
Interestingly the board they sent me was a new revision, 520-1057-00 compared to the older board 520-7017-72 and has some slight differences. Hopefully these changes are for reliability rather than cost cutting.
Oh and while I was there I replaced 2 more GI lamp sockets that had exploded, that's 10 now replaced
