Fixing Drop Target Reset Issues

Related Config File Sections
drop_targets:
drop_target_banks:
psus:

Sometimes your drop targets or drop target banks will not reset reliably. This often has mechanical reasons but it could be also caused by a stressed power supply or bad electrical wiring. Try to rule those out or fix them first. However, you still might have issues afterwards and we can ease them a bit in software.

Configuring PSU Magic

Behind the scenes MPF performs some magic for you to prevent stress on your power supply unit. The default should be fine for most machine but if your PSU is very weak try this config:

Configuring Pulse Times

Increasing the pulse time on your reset coil should help with reliably resetting your drop target or drop target bank. However, it will also cause mechanical stress, heats up your reset coil and might draw a lot of power out of your power supply.

One solution to this is to lower default_pulse_power to something between .5 and .8. Your hardware will PWM the pulse and you can use much longer pulse times without too much stress on your hardware. Also reduces the sound caused by the reset.

You can try something like this:

Resetting a Drop Target Multiple Times

If all the above does not help and you got an old mech which somehow does not like to snap in place all the time you can also try to trigger the reset multiple times. MPF will not reset drop targets or drop target banks if they are already completely up so this should not cause too much stress.

The following example will try to reset your drop target bank up to three times on ball start:

drop_targets:
  front:
    switch: s_drop_front
  middle:
    switch: s_drop_middle
  back:
    switch: s_drop_back
drop_target_banks:
  vuk_bank:
    drop_targets: front, middle, back
    reset_coils: c_drop_reset
    reset_on_complete: 1s
    reset_events:
      ball_started.1: 0
      ball_started.2: 1s
      ball_started.3: 2s
      machine_reset_phase_3: 0
This example is tested to be valid MPF config. Additionally, our integration test passed. Click to show the test and full config.
switches:
  s_drop_front:
    number:
  s_drop_middle:
    number:
  s_drop_back:
    number:
coils:
  c_drop_reset:
    number:
drop_targets:
  front:
    switch: s_drop_front
  middle:
    switch: s_drop_middle
  back:
    switch: s_drop_back
drop_target_banks:
  vuk_bank:
    drop_targets: front, middle, back
    reset_coils: c_drop_reset
    reset_on_complete: 1s
    reset_events:
      ball_started.1: 0
      ball_started.2: 1s
      ball_started.3: 2s
      machine_reset_phase_3: 0
##! test
start_game
advance_time_and_run 1