Bally ProVideo Poker - DBV issue

[MarkInAz]

I've acquired a Bally Pro Video slant top poker machine but the 145-SH is acting up.  The machine came to me with a dead MPU battery.  So I replaced that, did a Saferam clear and the machine now work good except for the DBV. 

The DBV is intermittent.  Most of the time it wont take bills but after playing it for about 10 minutes it might allow you to feed one or two bills, but then it stops again.

I've checked and wiggles all obvious cables, replaced the 145-SH with a good 200-SH but nothing helped.  At power-up you can hear the stacker go through a normal cycle.  When it feels like working the green LED will illuminated but the stacker does not cycle again. At all other times the green LED is off.

Any ideas?  I'm still thinking its a bad wire or socket somewhere. 

I ran the Output Test and did see the DBV LEDs illuminate, both red and green.  But how do you use the Input Test to check the bill validator?

Thanks-

[StatFreak]

Check for an intermittent open in one or more of the wires in the harness.