elfyhead
New member
I posted about this about a week ago, but have sleuthed a bit more since then, and thought I'd post in a separate thread (with more precise subject) to see if I could get some help.
My TAF Swamp Release coil is stuck on on power-up.
Here are the things I've done to try to fix it:
1 - Replaced a blown F103.
2 - Replaced the coil with a new AE-27-1200 (coil paper was burned, and it was shorted across the lugs).
3 - Replaced a bad Q20 (also replaced Q19 for good measure, though it measured good).
4 - Replaced U2 (even though all three of the other solenoids on the circuit worked, I thought I'd try it).
5 - Checked D5, R22, R23, R24, R25, R256 - all good.
5 - Reseated J113 on both sides.
6 - Checked J122, and wiring on the drive side, by unsoldering the blue/yellow wire at the coil, and externally connecting a wire directly from the pin in J122 to the drive side of the coil.
None of this made any difference. I have a fuse that is working, a coil that is good (13 ohms across the lugs), power to the coil (obviously since it's stuck on), good passive components, a good 74LS374 (U2), apparently good connectors (J107, J113, J122), good wiring, and yet the coil is stuck on. All three of the other coils/motors on that 74LS374 still work (Thing Eject Hole, Bookcase Motor, and Thing Motor), it's only the Swamp Release that is a problem.
Any help would be greatly appreciated.
My TAF Swamp Release coil is stuck on on power-up.
Here are the things I've done to try to fix it:
1 - Replaced a blown F103.
2 - Replaced the coil with a new AE-27-1200 (coil paper was burned, and it was shorted across the lugs).
3 - Replaced a bad Q20 (also replaced Q19 for good measure, though it measured good).
4 - Replaced U2 (even though all three of the other solenoids on the circuit worked, I thought I'd try it).
5 - Checked D5, R22, R23, R24, R25, R256 - all good.
5 - Reseated J113 on both sides.
6 - Checked J122, and wiring on the drive side, by unsoldering the blue/yellow wire at the coil, and externally connecting a wire directly from the pin in J122 to the drive side of the coil.
None of this made any difference. I have a fuse that is working, a coil that is good (13 ohms across the lugs), power to the coil (obviously since it's stuck on), good passive components, a good 74LS374 (U2), apparently good connectors (J107, J113, J122), good wiring, and yet the coil is stuck on. All three of the other coils/motors on that 74LS374 still work (Thing Eject Hole, Bookcase Motor, and Thing Motor), it's only the Swamp Release that is a problem.
Any help would be greatly appreciated.