Hi there!
This is my first posting on this forum
I recently swapped playfield on my #TAF, and everything works fine except the solenoid for the swamp release #28 in test mode. (Do not work in gameplay either).
I´ve done the following so far:
- Checked fuse. Working
- Checked solderlugs on coil. Everything is okay and it has correct power.
- Grounded the coil while in test mode and the coil fires
- Checked the connecters to PCB. Everything is okay.
- Checked the TIP102 transistor in Q20. Could not get any reading on my meter, so I changed the transistor. Solenoid still not working.
- Changed the Q19 transistor (pre-driver). Solenoid still not working, so I thought maybe the problem is further upstream on the board. (I´ve never fixed anything above this point on any board before..)
- Tested the U2 chip and leg 4, and it has a constant + 4,95 volt, as many of the other legs on U2. There is no pulse from leg 4 on U2 - except the constant +4,95V, when running the solenoid #28 in test mode.
- Tested R22, 23 and 24. Constant +4,95V. No reading on R25.
- Rechecked TIP102 at Q20. Working. 70 DCV.
- Checked transistor at Q19. +4,95V
Does anyone has a clue or suggestion to the problem? Do I need to change the LS374, since there is no pulse in test mode??
I´m going crazy.....
Regards
Simon