Symptom: Pac-Man looks drunk  Game plays fine, but (1)there is a faint band rolling through the picture (2) a heavy black bar rolling through the picture with a loud hum heard on the speaker (3) a thin band scrolling thru the picture with or without an accompanying hum (4) a flag-like, almost invisible weave/wave going across the picture. Cure:
If you want to fix it one time & forget it, then change the 4 block
fuse holder & Scotch-Brite the fuse ends.
Solid Pac for a lifetime.....forget the caps on the pcb other than resoldering C7 & C8, as these sometimes have a cold soldered leg, about 2 percent of cases, but nevertheless a possibility.
As you can see from the picture of 2 old Amp Pac connectors at the left, the weak solid, but flimsy pins in the Amp housing are very stressed & scorched. In fact, only 5 or 6 pins are still clean & tight looking, which is what is needed for a good connection for the AC to pass through to the pcb unscathed. This connector can cause many other symptoms in the Pac series from intermittent troubles to missing a color, or even a few cases of it causing a no sound symptom. The most common is the 60hz hum bar in whatever way it chooses to manifest itself, though. I've even found it to be the cause of losing video altogether in a case where a tech brought the whole game into the shop complaining about the monitor not working in it, but working fine in another game in his shop. He was sure he had some sort of wiring trouble in the cab that he could not find, and in fact, it was a wiring problem since this edge connector was causing a floating video ground to the monitor. The parts necessary to do this are on the "Parts Page".
The fuse block is $4.00 & the Molex connector is $15.25 and
purchased together they are $19.00 plus shipping.
All the help you will need with Pac games |
Next, get a Molex 22/44 edge connector with split pins (same as Jamma) and cut the wires about a ¼" up from the old never was a connector, one at a time & transfer them into the same positions in the Molex edge connector.
When one of my ops has a Pac series trouble, you can bet it is
on-board, because Molex keeps on ticking & the newer heavier fuse
blocks last & last, unlike the flimsy ones originally installed.