Sync problem

I found a machine with a monitor that has seen better days. I'm planning on replacing it but it has sync problems. Is there a hard and fast rule about sync? ie. is this a problem with the monitor/chassis, or could it be on the main board? Monitor is a WG K71xx.

Could be various things. Could be a bad pcb (least likely I would say), bad wiring, or a problem with the monitor. It could be fixed with a simple cap kit.

I would check the wiring first and then do a cap kit. After trying to adjust the vert and hor. hold of course.

Main rule is, make sure the sync line from the monitor is connected to the arcade board.

would a jrok sync cleaner help or is it too early to tell? i won't have a chance to check out the wiring till tomorrow at the earliest.