1 month old Black Knight Sword of Rage Premium that I've had a frustrating issue with for several weeks now. Currently working with Stern tech support and my distro who I bought it from, and all have been great, but since I'm still working through it I wanted to get some other thoughts since someone might have an idea we haven't considered.

The issue is: Randomly anywhere between 5 minutes and over an hour into playing, the knight shield will go into the down position despite having the Lock lit or a monster mode ready to start. Confirmed with Stern that this should never be the case, code-wise. Eventually I noticed that most of the time, the upper red GI lights also go out when this happens. Once a ball drains, or if I hold the flipper for a whole and then hit the other flipper, it sends a signal to reset/fix the node, which fixes the shield, however the lights remain out until I either power the game off and on or go into the Service menu to fix it.

Digging into the Service menu when the problem happens, there is almost always a Tech Alert for Overcurrent Protection - Upper Red GI. If I go into the Node test, it is flashing on Node Board 9 indicating a problem and mentions the Overcurrent Protection. When I run the test, it checks out fine and the lights come back on, and the shield also fixes itself.

Two things complicate the situation more. 1) Out of the 50 or so times it has occurred, ONE time it happened on the upper white GI instead of the red. 2) Out of those times, on about 5 of them, the lights stay on fine but only the shield drops down and fails to be up when it should. No Overcurrent Protection is triggered in the service menu when that is the case.

For my own peace of mind, I swapped Node Board 9 with 8, however, it didn't help anything and the error still occurred. Also, FWIW, I unplugged my speaker lights and flipper button lights but that didn't matter either, and the error still happened.

Basically, where I am at this point is taking upper red GI lights out one at a time and seeing what happens. The really frustrating part is, it can take well over an hour for the problem to happen, so it's a really arduous process. For example, the other day I took all three of the ones out of the upper backboard piece where they shine out over the playfield, and it didn't error for several hours. I figured maybe one of those were the issue, so I added one back in, then had no problems for another hour...added the second back in....still no problems for an hour...then finally added the last one back in (figuring this last one to replace MUST be the problem light), but STILL no problems for another hour. Then the next day...boom, Overcurrent Protection triggered.

I have also looked for anything obvious like a cut wire insulation or pinched wire, or loose pin, but have not noticed anything.

I'm dreading the countless hours ahead of going bulb by bulb, especially for the ones tucked under the upper playfield (really hope I can remove them from underneath when lifting it up to the service position). And in the back of my mind I still have my doubts about this approach, since I've had the issue on the white upper GIs once, and a few times of just the shield failing with no light issue.

Frustrating to have had the game for 4 weeks, and the glass has been off for almost 3 of them. I bet the problem was happening right away as soon as I got the game, but I wasn't familiar enough with the shield/game code rules or how the lights were supposed to look to notice that it was happening.

Any thoughts on other things I can test or try, or any different thoughts on what may be the problem?