The right flipper won't fire, although all three coil lugs show about 48 V DC.
One flipper dead with full voltage at the coil: cracked joints at the flipper relay
Cause: The flipper ground path runs through the flipper relay on the solenoid driver board to the flipper button. One side of the relay wasn't passing ground to that flipper because of cracked solder joints at the relay pins and at J2 pin 1. The joints looked fine.
Checks
- Start a game and measure J2 pins 1 and 2 to ground: the working side shows the switched voltage and the dead side doesn't.
- Watch both sets of relay contacts close when a game starts.
- Look for burnt traces near the relay, and wiggle the connectors next to it.
Fix
- Reflow the solder on the relay pins and the J2 header pins, even if they look good. Clean the relay contacts if they look dirty.
Systems
Games
Related tips
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- One flipper dead: open reading across the hold winding was a bad solder joint
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Source: Pinball Repair help group!! (Facebook group)