Go into switch test and see which switches are registering. One that should depending upon the position of the wheel is SW41. This switch is triggered for half the rotation of the wheel and is not triggered for the other half (the two blue 10Ks on the wheel form the dividing line.) You can rotate the wheel to either close or open the switch. If you rotate it to open the switch and while sitting there it goes back and forth showing the switch open and closed, then you have a problem with the opto on the Mystery Wheel.

Other diagnostic procedures for the wheel:

https://pinside.com/pinball/forum/topic/cyclone-mystery-wheel-problem#post-810733

Replacing the opto is pretty easy though I'd have to go look up which one it is.

GLM makes and sells a replacement board which was used in a number of other games (and is the one sold by Marco BTW):

http://www.greatlakesmodular.com/index.html?http://www.greatlakesmodular.com/products/pinball/sy11smd.html

You may want to send them a note asking if/when they will have more stock if you don't want to go the component repair route.

viperrwk

I should have also mentioned that you should try cleaning the opto first with iso alcohol and see if that solves your problem.

viperrwk

The fact that it shows it stops on the blue 10k when its not and says 256 in the P4 display shows the opto is not being read properly. First try cleaning the opto. If that doesn't solve it run the other diagnostic procedures I linked to in the other thread. Also check your connectors as suggested but this is most likely either a dirty or bad opto.

viperrwk

Watching your video, to me it is pretty obvious it is an opto issue.

The fact that the "H" appears in the P4 display and there are times when the wheel goes around where it works properly (gets to 200 and then resets to 0) shows that the switch is being read on the MPU board. But then there are times when the wheel goes to 256 and there's no H in the display so it is lost. It then turns until it can find home - sometimes it can, sometimes it can't. That sort of inconsistent behavior says opto to me.

From the manual for the Mystery Wheel test:

"...if the home switch (opto) is not working, the number (on the P4 display) can go as high as 256."

As I said, put it in switch test, turn the wheel until SW41 is tripped and observe it while it's sitting there. If it's not rock solid, it's an opto issue. It could be a dirty opto, could be a connector issue, could be a voltage problem, could be a bad opto. Easiest and simplest things to try first are cleaning the opto and checking/reseating the connectors. If that doesn't solve the problem, check the voltage next. If that is ok, you either need a new opto or opto board depending upon how comfortable you are with soldering.

If it were a problem with the switch matrix on the MPU, it wouldn't work at all.

viperrwk