Locked on coil, tried most things

[robm]

I have an Addams with 2 locked on coils (left magnet Q44 and left sling Q48)

I have for each one

Replaced TIP102, 2N5401 (twice)

Checked traces, continuities, diodes and 4 associated resistors - all OK

Replaced 74LS375 U5 chip, checked continuity for each leg

Still locking on.

The thing i dunno about is when i do the test for a 2N5401 (black lead on centre leg, should see 0.4-0.6V on either leg), i get 0.6V for the right leg (looking at the board) but 0.9V for the left leg (all the ones that are OK are 0.6V) - these were tested before i put them into the board, and both legs tested at 0.6V

Any help please?

Thanks

Rob

[dj10555]

Hi Rob,

The magnet problem could be due to a faulty TIP36 on the magnet board under the playfield.  Have you tried replacing the associated diode on the driver board linked to the TIP102?

regards Derek

[MartyJ]

Just further from Derek's idea, I take it you've checked both coils (ohms) as well?