My possessed F-14 is haunting me again. My first issue was a locked on coil - the upper diverter. It locked on to the point it melted the coil sleeve. I replaced Q78 & Q79 and it still locked on. I thought it might be a bad 7402 in U50. My friend removed the 7402 and installed a socket at U50. I put a new 7402 in and now both the upper and the lower diverter coils lock on with power. I have unplugged IJ19 so the coils don't fry and keep a meter on those pin (75 volts to each).

This is where it gets weird - for me - which doesn't take much. I used my logic probe and got the following:

PIN 1 = NULL
PIN 2 = LO
PIN 3 = LO

PIN 4 = NULL
PIN 5 = HI
PIN 6 = LO

PIN 7 = LO
PIN 8 = LO
PIN 9 = LO
PIN 10 = LO
PIN 11 = HI
PIN 12 = LO
PIN 13 = NULL
PIN 14 = HI

I think on the 7402 PINS 1, 2 & 3 are for Q76/Q77 and PINS 4, 5 & 6 are for Q78/Q79. I have different readings on the logic probe for these pins but both coils are locked on. Maybe the new 7402 is bad?

Attached is the connection and truth table for the 7402.

As always - thanks in advance.
7402 (resized).jpg

SOLVED

It was indeed a bad 7402. I replaced it and the gremlin is gone - for the moment.