So.....

If its not the optics themselves follow the wire..... something in the optic circuit is disconnecting, and from the information provided it seems to be related to the physical movement of the handle and/or subsequent vibrations into the rest of the machine that is causing the disconnect to happen. It issue doesn't have to be at the optic end and by using two different sets of optics with different means to couple the optics you have pretty much ruled that end of the problem out. There is still the other end of the wire...... the connector that it plugs into, then the MPU board connects into the motherboard..... we just need to keep following the problem backwards like we did with your reel errors.

I would even suggest you pull the MPU board and clean the edge connector on both sides with a white eraser to eliminate any potential issues there. Spray some contact cleaner into the edge connector (power off of course).

Great idea, I AKM going to trace the wires with my meter.

I have cleaned the connectors, however I will check everything out.

I just installed the TITO at Home board on my Konami K2V. As far as I know, you need an addon to make it work. titoathome_dot_com
If I take out the time that I was being an idiot during the programming, it took me less than 30 minutes for the basic setup. After that I did a few more passes on the settings that were nonessential for the operation of the TITO device, and more towards what was printing on the ticket and setting up the free play options. When you buy suck a device, the instructions for setup are included. If there is a way to do this without an external device, maybe someone else can help.

So.....

If its not the optics themselves follow the wire..... something in the optic circuit is disconnecting, and from the information provided it seems to be related to the physical movement of the handle and/or subsequent vibrations into the rest of the machine that is causing the disconnect to happen. It issue doesn't have to be at the optic end and by using two different sets of optics with different means to couple the optics you have pretty much ruled that end of the problem out. There is still the other end of the wire...... the connector that it plugs into, then the MPU board connects into the motherboard..... we just need to keep following the problem backwards like we did with your reel errors.

I would even suggest you pull the MPU board and clean the edge connector on both sides with a white eraser to eliminate any potential issues there. Spray some contact cleaner into the edge connector (power off of course).

Optics for the door, and door tester. 

https://youtu.be/pSEfqwQ50DE

David, I see you have the optics mounted on a box so that they're always closed (unless you block the path with something) rather than them being mounted in the machine like they normally would have been.

That's fine, let's work with that. If you place your optics box on a solid surface that isn't affected by the physical movement of the handle mechanism, does this issue still happen? If so, you then likely have a loose wire connection (or an intermittent short as Jay suggested) for your door circuit that is causing the machine to think that the door has been briefly opened when you operate your pull handle.

That is my tester, I built it for diagnostics. The door and cabinet have their own optics. It's a plug in, unplug system, nothing is hacked, butchered, just plug and unplug. The optics wiring is "factory".

Basically I have two sets of optics.