I actually didn't realize there were optos in there.

Raise Iron Monger and just check the optos in test mode. If they don't work in test mode replace them. You can jump them with a test wire in test mode to make sure nothing else is wrong and to get a test beep. I've had to replace a couple and it's not a big job. They fail so rarely it's easy to overlook the obvious. It is a cool set up. The top opto is there just to register hits in case Iron Monger is half way down.

Buddy of mine has this periodically on his IM. His monger still wiggles a little but its actually stuck and not moving enough. His problem was the wires for the light mod getting in the way. Not sure if this would be your issue to or not but something to look for.

Im not very good with tech.. But isn't that a sign of a shorted diode somewhere?

I was able to fix my monger issues by putting a washer on each post that holds the monger to the assembly between the clip on the end of the post and the back side of the assembly. That way the monger is always the thickness of the washer closer to triggering the optos. Also, make sure the metal piece at his feet with the blue rubber isn't bent out too wide on each side. If it is, it can hit the edge of the metal frame around the monger an keep him from going all the way back when hit at certain angles, thus not triggering the optos behind him. Mine never misses a hit now.

That's interesting. What happens when you test the Iron Man #2 switch in test mode? I would have assumed that is the next switch in a row and that you also have a bad switch diode but if there not in the same row it might be something else like a ground short. Since you have determined the optos are bad I would go ahead and replace those first and worry about the other switch after that.

Raising this thread from the dead.

Just has this same thing happen on my IM. Did the replacement opto's fix the problem or was it something else?

I've jumpered the existing ones to get them to register in switch test mode. I cannot get them to activate when blocking the light path. I also see no light from the opto's when viewing them through a digital camera.

Mine was not registering any hits, replaced all optos and that fixed my problem