Help. Old time EM guy trying to help a friend get his free Night Rider working. Game is at his loc, half hour away. Have installed new rectifier board at the transformer and all voltages are there. Game has a Stern "100" MPU board. I get a flicker then 7 flashes on the LED....with a longish pause after the first and second flash. No further boot-up, but I do have GI lights and the first press of the test button seems to go into lamp test. No displays working at all. Where do I go from here?....SDB?
Bob, In Vt.

Thanks all for the responses so far......will have owner check fuse on underside/flippers, also make sure a ball is in place anyways. test button has no effect after first press to go into lamp test. Will also reseat connectors. Is there a test point on the displays to look for 190v?
Bob/Vt