Pacman-Troys-WG-K4600

Issue: Colored horizontal lines through text and static pictures (not sprites).

I've cleaned the edge connector contacts and swapped the VRAM addresser board with a known working one. No dice.

Possibilites:

1) Edge connector needs cleaning/repair. The edge connector on this board has been repaired before and has some burn spots. It has a bad 'finger' that is in need of repair with the metal contact folding over in one spot. Probably not the issue causing this, but needs repair at some point.

2) Bad 2125 ram. This is from some repair logs on Mike's arcade. He did have a picture or two of the lines, and none of them looked like the issue here, so it's low on the probability list.

3) 74LS283 (NTE74LS283)@1-H bad. Could also be 74LS174. From the Pacman repair FAQ. This one is more plausible than #2.

4) Bad VRAM addresser board (suggestion from KLOV)

5) 74LS161AN @ 3R (NTE74LS161A). We have a winner. See picture below. Chip legs are very rusted/corroded. I took it out and cleaned the legs and reseated it and the green lines went away.

Issue #2: Screen 'blinks' and rolls horizontally (technically vertically, but the monitor is vertical in the cab.).

Possible remedies:

1) Replace HOT and VR. Tried this, did not do anything.

2) Found this KLOV article http://forums.arcade-museum.com/showthread.php?t=34097&highlight=4600+roll. It states that replacing the following parts will fix it:

C621 0.1 uF 1.5KV Paper - Sub in a film. This is an Axial capacitor that looks like an electrolytic, but isn't. The Polyester film cap can replace it 0.1uf 1500+ volts.

C633 2.2 uF 50V bipolar - mine was an 85 degree

Here's another article that draws the same conclusion. This one lists a part on Mouser (http://www.mouser.com/Search/ProductDetail.aspx?R=940C16P1K-Fvirtualkey59850000virtualkey5984-940C16P1K-F). Mouser Part #5984-940C16P1K-F

http://forums.arcade-museum.com/showthread.php?t=80892&highlight=4600+roll&page=2

Here are the positions of the suspect caps:

And here's what they look like. C621 Paper cap 0.1uf 1500V.

C633 2.2uf 50V bipolar:

And here's another suspect looking connection (exhibit A):

FIXED! Here's the chip that was causing the colored lines: