Did you replace the inter board connectors (40 pins)?
IC4 is for the last set of regular solenoids (13 thru 16).

The special solenoids are in the upper left corner of the driver board.
IC's 6, 7, 8 & 9.
Pre-driver transistors Q1-Q3-Q5-Q7-Q9-Q11
Driver transistors Q2-Q4-Q6-Q8-Q10-Q12
Make sure the switches are open for the pop bumpers and slingshots.
The coils stay energized as long as the switch is closed.
Attached are files for Fire Power, but the schematics are the same.
The special solenoids are in the lower right part of the schematics.

Williams_System-6-7_Driver-Board_layout.pdf

Williams_System-6-7_Driver-Board_schematic.pdf

I would also recommend using a Bridge Board....
http://www.inkochnito.nl (click on the bridge board image)

and a Special Solenoid Saver board....
https://nvram.weebly.com/repair--conversion-kits.html

While you are at it, add a nvram board (no more batteries needed)...
https://nvram.weebly.com/

These all have IC8 in common.
I'd start with replacing IC8.

Are you sure the chip is inserted in the right way?
Is the soldering work at IC8 perfect?
The other possibility is IC9, because it has the Game Over line.

IC6 is a 7408 chip
IC7 is a 7408 chip
IC8 is a 7402 chip
IC9 is a 7402 chip

First re-check Q5 and Q6.
After having a wroung chip in IC8 there might be a problem there.

Check input signal at IC6-pin 12 (should be high I think).
You can compare with pin 2, 4 or 10.
These should all be the same (playfield triggers)