S+ Winner Paid 0 Credit & Coins Played blank

[Queen Joy]

My husband and I bought two IGT S+ machines in November from someone on Facebook Marketplace. One worked when we got there and eventually the owner got the second one to work so we went ahead and bought them both. We need help with the one that only kinda worked when we bought it...

This is all new to us and one night while googling for help I suddenly realized that the numbers displayed in Winner Paid were error codes! (yes, this was a spur of the moment purchase with no knowledge of slot machines other than playing them) The error code was 12 and we replaced the battery. We tried to go through the steps after replacement and discovered that we needed a jackpot reset key in order to go any further. We have also used a RAM clear chip and when that didn't work discovered with help that the problem might be the door optics. And by "didn't work" I mean the lights would come on but the candle flashed and you could not get coins to register.

Tonight we installed the door optics and the candles no longer flash, we can add coins and the wheels spin. Winner Paid shows 0. Coins Played is blank. Credits is blank (but we can still play using credits). Insert Coin is lit and Coin Accepted lights up when coins are entered. We can hear the number of coins being played, and hear the coins/credits paid -- although the number of dings doesn't correspond to the number of coins won.

We would love some guidance. I'm good at Googling and telling him what to do, but in this case my Googling hasn't resulted in what we need. I would appreciate your help!

[knagl]

Let's work on one machine at a time. Please pick one of them, tell us which one it is, and tell us exactly what the issue is that you're having.

[Queen Joy]

The one on the right in the picture is the one in which we need help. The one on the left is totally fine. I included this working machine in my picture. I only wanted help with one machine, I'm sorry if it looked like I wanted help with more.

The machine on the right currently accepts coins, does not not show Coins Played.

[Stayouttadabunker]

Blue ,Brown, Gray, Red, and Green are the colors of the wires on the harness that connects to the back of your reel glass display panel.

You will see those colored wires run into a black plastic Molex connector and plugged upright into the display panel just to the right of the coin comparitor.

You see that lamp that lights up the .25 cent display?
Look just below it and you will see that 5 wire connector.
Make sure it is fully pushed up into the display panel's connector.

Below is a photo of the Molex connector that has the colored wires and connected to the reel glass display panel.
Click on photo to enlarge if needed...>>>

[Queen Joy]

We checked the display connection and it's plugged in -- not loose at all.

Anything else we should try? Thank you!

[Stayouttadabunker]

Try swapping the known good display panel from the other cabinet into this machine.

If it works, then you will know the harness and colored wires are okay (not broken) and that the
problem display panel is no good.

At that point, you could place a WTB ad in the Classified section of NLG for another working display panel.