The lower left flipper is very weak and nearly dies when the bulldozer motor runs; in flipper test the low-power setting can't lift it. The coil is new, the mechanism is rebuilt and the coil works fine on the other side.
Lower left flipper weak, worse when the bulldozer runs: cabinet opto board
Cause: A faulty (or dirty) cabinet flipper button opto board, not the power supply.
Checks
- Swap the left and right flipper opto boards (both must be plugged in); if the weak side moves, the opto board is the fault.
- Clean the opto slots before replacing anything.
Fix
- Clean the opto board, reflow its solder joints, or replace it.
Systems
Games
Related tips
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Source: Pinball Repair help group!! (Facebook group)