IGT S+ Endless 61-1 code

[Jimmyjackpot]

New Member here who needs some help.
I’m a rookie interested in the hobby of bringing some of my favorite slot machine titles back to life for use in my home.
I presently have one working S+ Machine (Double Double Diamond).
I recently acquired a second S+ machine at an estate sale (Red White & Blue).
I have no history for this machine.
I have tried many of the suggestions I find in this forum along with New Life Games with no positive result.
The appearance is very clean.
It lights up when powered up and shows the 61 code.
I press the white test button for 3 seconds and get a ding sound followed by 61-1 code.
I then close the door and press the door latch down firmly.
I then turn the jackpot key, and nothing happens.
It shows 61-1 and will not get beyond that.
I have confirmed alignment of the door optics. (Using pencil marks on the door and the cabinet).
I have tested the optics and have no light emitting from the door side. ( I used my camera to do this on both machines and see the pulsating light on my good machine and no light on this one).
I then confirmed the correct optic is on the door side (Red & Black).
Then I swapped the optics between the 2 machines and the good ones do not work on this machine and the ones from this machine now work on the good machine. (again, used the camera test).
I have looked at all the wiring and found no obvious breaks, disconnects, etc.
I studied all plugs for loose pins and solid connections.
I removed the CPU tray and found the appearance to be much better than my working machine.
The Battery tested @3.20 volts.
I removed the CMOS prom for 10 minutes, then reinstalled, powered the machine, got the 61, pressed the white test switch for 3 seconds, got the ding and 61-1, closed and fully latched the door, then turned the jackpot key with no positive results.
I then removed the CPU from both machine’s and changed the Game, Reel, and CMOS proms between them. When I installed them, the Red White & Blue CPU worked in my good machine and the CPU from my good machine did not work in the Red White & Blue.
During this process I broke a pin off the Red White and Blue game prom. I ordered a replacement (SP731) and a clear chip ( IGTS +Clear).
When I received them, I proceeded to clear the system and start over with no positive result.
I then decided to swap the Jack Pot switches between the 2 machines
The one from the Red White & Blue works in my good machine and the one from my good machine does not work in the Red White & Blue either.
Any thoughts on how to get this issue resolved will be appreciated as I have exhausted my limited knowledge.
Question…. Taking into consideration what I have tried, why is the Jackpot Switch not functioning???
More Info: The Red White & Blue does have a bill validator. Could this component interfere with the function of the Jackpot switch ?

[slots4home]

Yes the jackpot key could be part of the issue. It could be a open door somewhere.
Is the bill acceptor door switch in tact ?
Has it been bypassed?

[Stayouttadabunker]

On the RW&B, does the number in the [Coins Played] lamp go out for a few seconds then come back on when you close the door latch?
If not, then there's something wrong in the optic wiring....or the optics themselves.
Check especially,  the green wire from the door optic back to the motherboard.
It's important you get to see the door emitter optic to shoot out infrared light while viewing with a camera lens.
If not, that means there's no power go to the door emitter optic.
Follow the ground wire from the optics all the way back to motherboard.

You must get the optic part of your system to function correctly to see the door closed or you will never get past the [61-1].

Of course, do not neglect inspecting the cabinet receiver optic for any breaks...replace if needed.