Arcade connection question

[Peenwheedle]

I have decided to restore a Pac-Man arcade that I found in an antique mall. It has all kinds of problems. The screen is showing lots of lines and stuff.

Here's what I don't understand and need some help figuring out why I must be an idiot! As you can see on the JAMMA pinout, the video signal goes over N, P, 12, 13, and 14. I suspected my harness was messed up (it looks like someone spilled coffee on it!), so I just bypassed the harness and used alligator clips to connect the video wires directly to the JAMMA board.

PERFECT PICTURE! So that was that. I ordered a new cable harness and.... same damn problem! I've toned the wires, made sure they are connected right, cleaned the PCB, etc. I just do not get it. Connected over my wires it works fine. Connected over the harness I get all kinds of lines and distortion on the screen.

Driving me CRAZY! Help me return this Pac-Man to its former glory!

 

[D.A.(Tony)Stewart]

I have decided to restore a Pac-Man arcade that I found in an antique mall. It has all kinds of problems. The screen is showing lots of lines and stuff.

Here's what I don't understand and need some help figuring out why I must be an idiot! As you can see on the JAMMA pinout, the video signal goes over N, P, 12, 13, and 14. I suspected my harness was messed up (it looks like someone spilled coffee on it!), so I just bypassed the harness and used alligator clips to connect the video wires directly to the JAMMA board.

PERFECT PICTURE! So that was that. I ordered a new cable harness and.... same damn problem! I've toned the wires, made sure they are connected right, cleaned the PCB, etc. I just do not get it. Connected over my wires it works fine. Connected over the harness I get all kinds of lines and distortion on the screen.

Driving me CRAZY! Help me return this Pac-Man to its former glory!

Check Video ground against GND- and earth ground. then verify Green Sync which is the more like problem.

 

[Peenwheedle]

Check Video ground against GND- and earth ground. then verify Green Sync which is the more like problem.

Yeah. I did that. Still no luck.

 

[D.A.(Tony)Stewart]

use tool to remove wire from connectors then jumper again as before , then test.
start with GRN SYNc, then test without / with jumper. if no difference then focus here.