Post a pic of your power supply. Measure the 5 volts on the power supply.

I would assume that your game had reset due to low 5 volt. This may have caused one or more coils to lock on, burning the F-5 fuse. Someone has replaced the caps on the power supply in the past. They did not use the correct one for C-10, it should had been 18000 uf instead of 15000 uf. Can you test the voltage on IC1 pin 10.

Check pin 10, should be about 6.45 volts DC.

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You could remove the large connector above the IC1 chip, but it's not necessary.

This is low. This voltage goes to the base of Q-5. Q-5 regulates the 5 volt line. So this is why you have 4.77 volts instead of 5.00. Anything under 4.85 volts will cause the cpu to stop running, when this happens coils lock on burning fuses.

Either Q-5 or IC1 could be bad, but before you replace anything do one more test. Test the voltage on IC1 pin 12, should be 26.7 volts. If this voltage tests is good I would replace IC1. If this voltage is low then I would replace D-1, D-5, D-6, C-7 and C-8.

What does the 5 volt read now?

4.99 volts is a lot better then 4.77 volts. Try playing some games, see what happens.

Is this at power up or at start of game?

So you have one of the transistors turning on or shorted out for the high voltage coils that are controlled by snubber relays. In the pic below I have high lighted the transistors for all of the snubber relays. If you leave the fuse out at F5 fuse holder and turn on the game, one or more of the snubber relays will turn on and stay on. This is not correct and why the fuse is burning. An easy way to find out which snubber relay is on is to do a voltmeter test. If you set your meter to DC volts and place the black lead under the ground braid, then use the red lead to test the transistors I highlighted. Touch the red lead to the metal tab of the TIP 122 transistors and you should get a voltage reading of @ 32 volts. The metal tab is the same as the collector lead of the transistor. If you find a transistor that reads zero volts, this will be your problem. Let me know what you find.

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Repeat same test but check Q-77 and Q-79 this time. These 2 are for the divertor ramp. Some games have these coils wired for 50 volts instead of 25 volts so if they are on 50 volts they will be on the same F5 fuse.

Houston we have a problem!

Ok go under the play field and cut off the purple/yellow wires from the two coils and cap with a wire nut. Replace the fuse F5 with a 2.5 amp slow blow fuse. Power on the machine and start a game. Everything but those two coils should be working now. Let me know what happens.

So like I said earlier some games are 50 volt (purple/yellow) and some games are 25 volts (red/white). I have always suggested to people to use the red/white wires to reduce the stress on the transistors. But in saying this you need to keep the purple/yellow chain connected and insulated so the coils down the line still have power. You can remove the purple/yellow wire that is connected to both divertor coils and use it to splice the broken purple/yellow wire.
For the low voltage to work, the divertors need to work smoothly, the pivot points need to be clean and oiled, clean coil sleeves and polished plungers. There is a service bulletin you should look over too.

https://www.ipdb.org/files/804/Williams_1987_F_14_Tomcat_Service_Bulletin_no_number_undated_to_resolve_binding_diverter_gate_assembly.pdf

Also you still have issues on the CPU board that need to be fixed. After you get the purple /yellow wire fixed, then run a coil test to ensure every coil works but the 2 divertor coils.

Test the 5 volts on the cpu board, let me know what you get.

This should go to the Yagov coil and then to the left outlane kickback. You can use any color wire but I thought you might have enough of the original wire to do this.