If you're using the IPAC instead of the JPAC....GET UTIMARC'S VIDEO BRIGHTNER!!!   I ordered mine a couple of months ago and just got around to installing it.  WOW what a difference.  All the games are as bright as the original PCB's, even through the smoked glass I have on my cab!
BTW the JPAC already has the brightner circuit
Get one NOW!!!  
http://www.ultimarc.com/vidamp.htmlDoug