Fliptronics flutter that new transistors did not cure: check the 1N4004
A flipper that double-flips and will not hold, even after new TIP102 and 2N4403 parts, can have a failed 1N4004 in the hold circuit. A clue is the 2.6k resistor reading low in circuit (about 1.8k) while testing correctly out of circuit; the bad diode read about 1.2 instead of 0.4-0.6.
Systems
Related tips
- Fliptronics: flipper will not hold up (flutters)
- Fliptronics II board components
- Fliptronics flipper coil wired wrongly
- Resets from damaged flipper coil diodes
- Testing the diodes on a flipper coil
- Always check the coil diode when a driver transistor has failed
- A cracked coil diode keeps killing its driver transistor
- STNG: diverter coils lock on during play
Source: Repairing Williams/Bally WPC Pinball Games from 1990 to 1999, Part Two, Clay Harrell (pinrepair.com)