Hi, I have an electrical problem that I can not find the solution in a road show. It activates the middle control on the left side of the maintenance coil. But the problem is not on the filtronic plate because if the disconnect of the sound board works perfectly , But if I connect the sound board appears 0.6 volts on pin 1 of the connector J-902 of the filtronic plate and I activate the maintenance coil, if I disconnect the sound card no longer appear the 0.6 volts And it works perfectly. Now check all the diodes and resistors of the sound board and I do not find anything wrong. There is some way to connect the coil without the maintenance coil. If anyone can help me I would appreciate it.
Sorry for the faults but I am Spanish and use the translator.

It is the # 36 middle left flipper that goes to the connector J-902-1, which is where I see the 0.6 v.