MEI Cashflow bill validator won't stay on unless pressing down on it

[knagl]

Hello everyone.

I'm helping a friend with a new-to-him Game King machine. It has a MEI Cashflow bill validator on it, and I've never worked on one of these before.

The machine isn't 100% functional yet -- it's got a dead battery on the processor board and he's going to get a replacement soon. When the machine is turned on it displays a "RAM ERROR" message, and some turns of the jackpot reset keyswitch and a press of the self-test button when prompted bring it to a "Main Battery Low / Options Verification Required" message. I mention that here only in case it has any relevance to the bill validator.

The bill validator does not make any cycling sounds when the machine is turned on. We've also noticed that it doesn't light up at all unless you press down and hold on the back of the validator head. When that is done, all three red/yellow/green lights stay on steadily.

A couple of questions:

I presume that the three lights on steady is not a good sign. What does it mean?

Any thoughts on why we have to apply pressure to the back of the validator head to get it to power on at all? Is there something broken or missing? Please see the following video for a visual of what I'm talking about:

https://www.youtube.com/watch?v=c3T9GLkIzLA

Thanks in advance for any help.

[sixcardmark]

It should not move when you press down on it.  Maybe the interface board is not inserted correctly.

[shortrackskater]

I had a similar issue - same game, same unit (intermittent) and the indeed the I/O contacts were dirty. 

[Stayouttadabunker]

3 LED lights on the head is not good.
The interface board has these spring-like contacts that touch against the MEI gold tabs.
You can clean the gold tabs on the MEI head by rubbing a white eraser on the gold tabs.
Note that when you pushed down, it came to life....so only clean the bottom gold tabs on the Mei.
This above, however, may do nothing.
This is why...>>>

The interface card that the MEI tabs are pushed onto, is a different story ...they are basically clinically dead.
They have little to zero spring life in them anymore.
Can you imagine being squashed on for like... the last 20 years? 
I'd be kind of flattened out too!
Best bet is to try to get a somewhat newer interface card.
Or maybe spray some contact cleaner onto the springy tabs, which may or may not, help promote better electrical contact.

Here's something else I try to do sometimes.
Pull out the cashbox, take out the MEI head.
Now you can pull out the interface card from the bill acceptor housing.
I like pulling with a hand underneath and a hand on top of the interface card.
Then with a Philips screwdriver, remove the two screws that secure the black plastic thumb holder from the circuit board.
You will see all the oval-shaped contact springs.
You can try to gently bend the ones a little outward that are more flattened than the others.
When you put it back together, hopefully, the ones you've re-bent push a little harder and get better electrical contact against the MEI head's gold tabs.

[knagl]

I appreciate the feedback, guys. Can someone post a photo or two of what their MEI Cashflow head and interface board look like? I'm almost wondering if this is missing a part or has something broken on it. The head physically moves when I press down on it like in the video, and it seems like the contacts on the back of the head are just gently sitting on top of the contacts on the interface board -- like there's nothing causing it to put any pressure on the interface card/contacts.

[shortrackskater]

Just remove the head... depress the lower bar and lift away. That gives you access to the board just in front. There's a little half circle where you just stick in your finger and pull out. Mine was a bit tight!
Hope this helps.

[knagl]

Thanks for the photos. I have removed the head from the machine and the interface board as well. I'm just trying to figure out what holds the back of the head down against the pins on the interface board. As you can kind of see in the video, the one on the problem machine really rocks up and down a lot in the back.

[Stayouttadabunker]

There's not really a whole lot of material that holds down the head in the correct position onto the spring contacts.
Where I've circled it is like a couple of cutouts in the sheet metal where the molded plastic extrusions and the locking bar on the head slide into.
There doesn't seem to be any slide/guide in the rear end of the box, but you do kind of rotate the head downwards as you push it in to the locking point.

I'm thinking possibly during the lifetime of this MEI validator; someone was pulling up on the head, without fully pushing on the locking bar when trying to remove it?
They could have worn or distorted the plastic nubs on the head, and now the rear end of the head isn't exactly in the downright position when it's locked into the metal cutouts?

[knagl]

Thanks Mark. I'll take a closer look next time I'm at the machine. I appreciate you taking the time to reply and share your insight.