Pac-Man/Galaxian Horizontal sync

[Hooligan93]

Hello everyone,

Having problems with Pac-man and Galaxian on a Jamma setup. Both games when connected to my Jamma Cabinet have horizontal sync problem. Screen is stable not rolling but video is skewed left to right (screen set for horizontal games). Monitor (WG K4600) is fine as my Ninja Gaiden has no horizontal sync problems.

I used one of Ian Kellogg's jamma finger boards and used Mike's Arcade DC pinout for pac-man. Sync is on the Negative Composite pins on the monitor. 12V is at 11.59V. 5v is set to 5.1v on power supply and lowest i found on the pacman is 4.9v at the end of the 5v power circuit.

The game will sync if I leave cabinet powered on and pull edge connector off and put it back on (found this out by accident) , but will not sync if powering up just by cabinet power switch. Seems like a power issue? Any suggestions?

PS On board reset switch doesn't work on both boards.

[Hooligan93]

Hello everybody, I figured this one out. Turns out it wasn't a problem with either Galaxian or Pac-man but a common problem with the WG k4600 monitor. My Ninja Gaiden worked just fine but was almost at the end of the horizontal hold pot. After much searching I finally came across an article written by Bob Roberts about monitor sync and the special quirks of the K4600. Here is the link

http://arcadecontrols.com/BBBB/slanted.html

I did what Bob suggested and set my Horizontal pot in the middle then set the plastic screw on the H/V daughter board to half a turn counter clockwise and my sync problems are solved. Bob also has a few other K4600 solutions included as well in the article. Hope this helps  others out in the future.

Now to fix the Pac-Man.