Faulty game board causes poor bill acceptance

[onesell]

I have been looking around on here for a solution to the poor acceptance and have found a couple of threads about the game board sure enough it was the game board in my case too.

I was wondering if anyone knows what component on the game board might be causing this or if anyone knows where on the board the B.V. is controlled so I can have a play to see if I can sort it.

Thanks
Richard

[stayouttadabunker]

You know what I'd do first?
Put the "faulty" board back in and see if the "Poor Acceptance" returns.
I suspecting a bad ground wire between the DBV and the motherboard instead.
I know it's a bit of work because you'll have to re-enable the DBV with a SET chip but after doing this -
you'll be sure it is indeed a component on the MPU board.
If the "Poor Acceptance" doesn't come back, then what happened is the RAM got erased and
cleared the "Poor Acceptance".
 or
Reseating the MPU board allowed the pins to rub off a little bit of
oxidation between the receptor and pins connecting the MPU to the motherboard , thereby
allowing the intermittent bill acceptance to go away.

Looking for the fault on the MPU requires knowledge of the
pin values of chips when reading them through an oscilloscope.
I seriously doubt anyone has any sort of documentation for those values except for
such guys like Cactus Jack or perhaps Ozzy.
One way you can find out those values (Which on my list, is exceptionally difficult and time consuming)
is to write down every single reading you get with an oscilloscope on every pin on the MPU board
relating to the circuitry of the DBV on a known "good" MPU- while in the operation of accepting a bill.
I'm talking about getting all the high/low or flashing readings from the pins of all the components along that line-
including all the pins of the eprom chips that are involved when a bill is accepted.
Then, comparing those readings with your "bad" MPU board...Arghhh!
Good luck...

[onesell]

Mmmm that sounds like it might be fun, I sure don't have the equipment or the knowledge to do that. I have had this problem 6 times recently I have workshoped a batch of machines that had WBA's in and have been refitting them with an NV200 a new BV made by Innovative Technology. Most of the machines I work on don't have the BV fitted or turned on because most of them come to me with heads that won't accept £ or € something to do with them being mag heads I have never really asked why they won't work. I hadn't thought about a bad connection though I will have to have a look at that and see what happens.

Thanks for taking the time to answer me,
Richard