I really want to thank both of you for helping me out. I have taken apart this slot machine trying to find the unlock handle issue, I did check out the door optics test and its working.
I thought this rogue wire may be the problem, it's located under the play button.
After I unplugged different wire harnesses, removal of the MPU, removal of the hopper, disassembling the buttons again, checked out the transformer, fuses, the issue is still ongoing. The wiring in the slot machine is not butchered, it is in excellent condition.

I have several wiring diagrams, maintenance books for the S+ and I have been studying them.

To make sure that I’m correct, This button is the one to the left of the hopper on the MPU board,(There’s a little slide plate on the cover and inside  there’s a small black monetary push button. My understanding if I’m doing it correctly, Is to hold it down 3-4 seconds after I turn the machine on. Once held down it makes a noise and then I can let up and proceed forward. This machine had a dead battery as well. I cut out the resistor that’s part of the charging circuit. I replaced it with a new lithium 3.6 volt battery and it worked great for a short period of time then turned it back on and nothing, except for that chattering solenoid after a few minutes. I’ just installed everything back in it and I’m going to check the voltages at the pins that were listed to test. I will post shortly the results.

A tower board intermittent short to ground could cause the tower lights to flicker or the door handle solenoid to chatter. Worse case it takes out a fuse. Optoisolator chips protect the main processor board.

CN4 pin 8 is the 9.5vac to the main processor board. Loss of 9.5vac will shut down the main processor board.

Did you power up the machine while holding down the "ALL RESET" button on the main processor board? The RAM may be corrupt.

I'm working on an 8116 now that had similar issues; LEDs and lamps flashing and solenoids chattering. The main board battery was bad, acid leaked on the board and the corrosion caused some traces-solder joints to open or short to ground. The memory decoder chip was also effected and must be replaced.

I'll typically check the voltages with the Molex's plugged in so the power supply is loaded.



 

Quite a bit of items, If that piece has taken a dump could that be the reason Why I’ve lost everything? Display, I can’t reset anything. The Only thing I get is the handle solenoid starts chattering after the machine has been on for a few minutes. I tested All the voltage outputs except for pin #8,(I didn’t understand that one) and they were correct. One moment it was working great, turned it off next day back on and a bright brick with fluorescent lights is All that works. I’m lost on these Universal machines. Any suggestions/Thoughts?