Will it start a game? Do you know if the displays are good? Every Sys80 I have had I did all the ground mods first, cleaned every contact, then fired it up. I am working on a Counterforce right now with similar issues. have you looked at the connections to the Displays? do they need to be re-flowed? I'd focus on 1 thing at a time. Does the test button start any of the tests? Lower PF shouldn't matter. I've had mine out of my HH and it still "worked"