Mint87RX7

Just got a used safc II, soldered everything in using the manual and 1300cc.com. When I turn the ignition on the **** lights up but not the screen. If i press the center joystick button it turns on all pixels, if I press it again it goes to a screen showing either OK or NG for different inputs and does respond to tps. of course if I start it, it runs like crap because it has the last persons tune in it.
Has anyone ever heard of a diagnostic mode or something for these? I got it cheap but the guy gave me his address so I dont think he knew it was bad or hes an idiot. I have spent hours searching google and cant find anything on this screen. Anyone have any ideas?
I have opened it up and cannot find any bad joints, only thing I see is a small burn spot on the screen itself but from searching that seems to be normal.