If you're getting the lamp test, the MPU has booted up properly. Also confirmed by the seven flashes. The pause between flashes sounds normal. Are you getting +190VDC on each display?
As for no ball kicking out/solenoids, is the fuse on the underside of the playfield ok?
No ball is necessary for any attract mode. IIRC, Night Rider does not have an attract mode but it's been 43 years....