"Insert Coin" flashing while door is wide open...huh?

[stayouttadabunker]

I've never seen this one onan S+ before NLG'ers! 

A .25 cent coin comparator stopped working, I replaced it with known working one.
I also changed coin comparator harness with a new one.
Still zero coin acceptance.
(What's worse is that the suspect CC AND CC harness works flawlessly in another cabinet I checked both items with!)

This is what gets me though...>>>When I open the door on the machine, the "Insert Coin" light on the door remains flashing?

Soooo... I checked the door optics right away and find that they are good because the "Insert Coin" momentarily goes out along with the "Coins Played" light simutaneously if I close the door.

Chips installed are: SP1227/ SS4927 Wild & Lucky 2CM

Any ideas? haha!

[CVslots]

I would suspect something is haywire with the MPU. I'm sure there's something that tells the machine "I'm ready for a coin" besides the door optics (or maybe in a chain with the door optics). Gimme a few...let me see what I can find...


Update: Ok...check Q5, then RP7, and U8 for any obvious signs of damage, they are all related to the Insert Coin lamp functionality. If not, it could be burnt traces on Motherboard.

If both MPU and motherboard are good, then it has to be in the wiring somewhere.

[stayouttadabunker]

Okay..solved it!

The problem was that the "Coin-In" optics wasn't sending acceptance signals to the MPU.
Simple solution was to just change the coin-in optics right? Well nope!
All they did was swap out CC's...I also found out that another floor tech had used a Clear chip on it !! ARGH!!! 

Sooo...the machine didn't have the coin denomination programmed into it
and the flashing "Coin In" light was due to the fact that the machine hadn't yet recorded a game played.
The internal accounting system was totally cleared and wiped out! 

Next time I go on vacation, I'm hiding the Clear chip!!! 

[CVslots]

Well, at least the S-Plus mystery was fun while it lasted!