coin / credit issue

[resolved, at least for now]

didn't find this answered anywhere, so...
when the coin switch gets flipped, the internal credit counter only rolls halfway to the next number, and then locks up. no credit gets counted to the appropriate led panel, either, and the start button does nothing. plus, hitting the switch stops having an effect at all after the first time.
not sure what's happened, as it was working before, and all i did was replace the coin return bezels and the 555 bulbs behind them. i tried putting the dead bulbs back in, just in case, but still the same thing is happening.
any ideas what's happened here?
-and i'm still in the process of repairing the monitor, so unfortunately i don't have any information regarding that aspect of things (it's currently disconnected)-

Try jumping the credit + & - at the edge connector and see if it credits up the credit display. Sounds like you have a short somewhere.

Try the service button also and see if that flips the credit counter,

disconnect the coin counter

thanks. i'm hoping to get at this tomorrow some time. i'll let you know how it goes.

[edit oct11] okay, i basically worked through it, disconnecting one thing at a time. it seems to be related to the led counter in some way, as disconnecting those seemed to solve the problem. might have been a dirty connection or something(?), because i hooked everything back up and it seems okay now. all is well. hopefully it's not some subtler issue that i'm missing completely.
thanks for all the help!