Coin Slot Problem

[StellarX]

I recently built my own arcade cabinet and it's been working great, but something that has really been bothering me is that some games refuse to let the coin slot work.

It works perfectly on many games, but seems like whenever i play a fighting game like Mortal Kombat series or X-Men, the coin slots just don't want to work (the 5 key on the keyboard still works!)

Anyone had a problem like this before or know of anything i could be doing wrong?
I'm using an I-Pac for my control wiring

[Zipper]

Do you have a credit board running from your coin mech? If so, does it have a dip-switch so you can set the credit pulse from 'short' to 'long'.
It may be that the game requires a longer pulse, or longer pauses between pulses.
It's the only thing I can think of. It has to be the coin-mech pulse if the i-pac works on other games, and the '5' key works on the keyboard with all games.
Good luck.

[StellarX]

Well i am just running wires directly from the coin slots to the ipac, i'm using the happs 'over/under' coin door and i can't seem to find any switch to lengthen the pulse hmm...

[Thenasty]

if lots of game works with one shot thru your coin switch, Mortal Kombat default this to be 2 shot (2 coins). Maybe this is what your experiencing. Set up MK to accept 1 coin instead of 2 or 3 coins thru the setup. This is justy a guess, cause I once wonder why when I put 1 credit, it does not give me 1 credit, I have to actually put 2 coins to get 1 credit...

[StellarX]

Well I have verified that it ONLY happens on games that require 2 or more coins for a credit, and i tried changing it to 1 coin per credit, but that didn't fix it, and i also tried changing the 'chute type' whatever that is but still no luck....

[Thenasty]

try doing this....Your switch might be intermitting. Do a test on the coin switch #5 and do this on the DOS prompt. Insert a coin and see if you see the #5 on your screen appears. Do it several times. This way you can see the output on the screen. Looks like you are the only one having this problem, so its not a MAME bug.