I have a late 70's Gottlieb El Dorado single player. It was working very well after a recent repair when suddenly it will no longer start. After the startup sequence, the Hold Relay (R) is supposed to lock in, which activates the playfield, returns the ball, etc. The hold relay on my machine is de-activating when the start sequence ends.
If I read the schematic correctly, it locks in through a NO switch on R (provided all the tilt switches are ok) and remains so until a NC switch on the Tilt Relay (T) opens. But I cannot figure why it's not locking in.
It works when engaged manually or when power is jumpered to the to the relay. Any ideas?