Die Hard Arcade Monitor Problems

[8bitnintendogames]

I just picked up a couple Die Hard Arcade machines, and one of the machines turns on and plays, but there is no red color at all. I have adjusted the red, green, and blue knobs on the monitor, as well as the contrast, but still no red. What can I do to fix this. I do have the other Die Hard machine, which has a bad monitor, but not sure what condition the monitor board is in. Any advice would be great. Thank you.

[MysteryRidahz]

Just curious, how much did you pay for them and where?

[8bitnintendogames]

I paid $40 each, so if worst comes to worse, I would sell the game board and cartridge, and convert the cab into something else, since it is a plastic cab. Thank you for the reponses

[madman77]

Any follow up on this? I'd be interested to see if it was a bad JAMMA harness or monitor chassis issue.