Quoted from Jakers:
Well, I'm out of ideas at this point as to what could be wrong with my middle target on the time expander. A new 10 onto board didn't fix the problem like I thought it would. I've found that if I unplug the optos under the playfield (the 12 molex connector) then plug it back in, the switch works fine for a few seconds, then starts freaking out, then stops working completely. Take a look at these two YouTube videos I took to see what I'm dealing with. Has anyone ever saw this type of behavior before? I've checked all continuity from the opto board to the CPU and all connections are solid. I've also replaced the sender and receiver optos with new ones.
Here is video of what happens when I plug the optos in and don't touch anything:
Here is a video showing the middle time expander switch working for a second and then stopping:
This is an easy one.
I have seen it dozens if times.
You are very close to perfection!
The optos are very slightly out of alignment on that switch.
Flickering is a sign that a slight amount of light is leaking past the interrupter or reflecting off something.
Push the led slightly up towards the top or mushroom switch side of the box.
You do this with the pc board mounted to the carrier with the 4 screws.
They bend very slightly, but enough to make adjustments. Dont break them off.
Or bend more towards the center of the interrupter.
Pull out the balls.
Lift the playfield and lean it all the way back onto the back box.
Fish out the plug for the opto carrier.
Test the assembled opto carrier live outside of the MPF assembly by itself with the machine on in test mode.
Its hard to see the DMD but you can hear the test.
You can plug it in and out live with the game running, it wont hurt it.
When your satisfied its perfect, reassemble the time expander.
Dont install it onto the playfield yet.
Set it in the bottom cabinet, plug only the opto harness in again to see if it changed.
If its all good, reinstall the time expander back onto the playfield.
Use black paper for the shroud.
All of the switches are proven to work, just need to be tweaked a tiny bit.
Youre almost there!