My Haunted house has a problem where once the it has been on for about 10 minutes or so I get playfield lights (The green 1-5 lamps) that start to flicker and seem to be getting power surges. They do not lock on they just start to fade to on but not full strength and you can hear a distinct hum as it surges. Then the Upkicker from the basement to the main level starts to fire randomly. If I disconnect the basement playfield I still get the same surges on the lamps. I have disconnected and reconnected the circuit boards multiple times to see they just aren't seated incorrectly but I get the same result. A power kit with all components in the bottom of the cabinet was installed about a month ago. I have had the grounding mods done but perhaps one was missed. I am a novice when it comes to troubleshooting electrical problems but I have a friend who can help. Any concensus on the root of the problem?

Grounding Problem?
Driver Board?
Connectors?

Thanks any suggestions would be most appreciated!!!