Seeing the same issue on a friends TAF.
Press left button, flipper holds until powering off, or letting game go into ball search mode (coils firing) or by repeatedly pressing right hand flipper button. Transistors all test ok in the board.
Curiously, the right hand coil was sparking and on investigating, have found a second thin (low voltage holding coil?) wire loose. Moved it around and now the flipper fires up when rh button pressed but immediately drops. Doing this after the left flipper has been energised, causes the left flipper to drop.
Suspect 2 issues at play. Dodgy rh coil and a bad transistor.
Question - which tip102 transistor to replace for the lower left flipper to release? Q9 or Q10
Skippy2904