WG7550 AVGA/JPAC PROB

[drumlogix]

Hi.

   I have put a lot of time (and money) into my mame cab project and i am now at the final stages. I got a WG7550 monitor w/ the remote control with pots on it. This is from an orig mk2 machine. Now I have tested the monitor alot on the orig mk2 pcb and it works perfect. I have built a very nice computer to use in the cab . also i got an avga and a jpac to hook monitor to pc. After building pc and hooking it up I turn it on and IT WORKS! well kinda. the prob I am having is the v-hold.  The display contantly goes either up or down depending on how i tweak the vhold pot. It seems WAY to sensitive. I cannot get it to actually "hold" the picture on screen. No matter how lightly i tweak it it only goes one way or the other. and just when i get it almost stable it starts scrolling display again. Now I am wondering why it does this with the computer and not the pcb. I can turn the pot when hooked up to pcb and there is a huge area where it stays perfectly stable. This makes me want to cry because I am so close to getting this thing working. I have removed all jumpers from jpac except the 15kz one. I also should note that this is happening in the bios menu and boot screens. I havnt been able to install xp yet because i have no onboard gfx and no extra agp card. and i cant hook up the avga to my monitor (out of range) or through svid to my tv (screen scrolls). does anyone have an idea? thanks so much for reading