My flipper circuit is good as long as I manually hold the K1 relay closed. I don't fully understand the circuit, but when the relay is closed, it supplies ground to the +43VDC flipper circuit and pinball happens. Schematics in the manual are vague, other than telling me that Q7 controls the relay.

Here is my conundrum: I tested the transistor Q7 (Darlington transistor SE9302) and all looks good with my DMM (compared to similar circuits) and I probed the K1 relay and the coil seems to be OK. Diode D23 acts a little but funny (and I think is in the circuit along with Q7), but I figure that might be because of a capacitor in the circuit. When I test with my DMM in diode mode, D23 (in circuit) reads 600 with correct polarity, but if I check reverse, I get a momentary "spike" on my DMM around 1500-1800 before testing open.

What am I missing? I took the cover off of the flipper relay and when I close the leads, everything works. I have +43VDC at the flippers. Something is either not telling the relay to close or the signal is not getting through. Attached is the only mention of K1 that I could find in my schematics.

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Problem solved. I re-flowed the pins on my power control board some time ago, and I apparently made a cold solder connection or two. I have had a fair amount of practice with my ne Hakko since then and I am much better now. Both my flipper and my display flicker problem are now fixed. Like always, first make sure the @#$^* thing is actually plugged in.

That's what I have been thinking. This one will probably stay in the hall of fame, but the next one I might not become attached to (said every pinball hoarder ever).