Did you try this with the bad coil leads cut?

That depends, if its the upper coil then Q-77 but if its the lower coil its Q-79.

This is a snubber relay board for firing high current coils. That is a 150 ohm resistor that is burnt on the relay board. This is for the rescue kick back coil. This maybe why you are burning F2 on the flipper power supply board. There is a single fuse holder under the GI fuse holder for powering these high current solenoids. If you remove this fuse and replace the other fuse and retest you can narrow this down to a board issue or a coil issue.

I think there is 8 of them, I have never seen the resistor burnt off like that so there maybe other trouble after you replace the resistor. There maybe a shorted TIP for this snubber also which would have left it locked on and could have burnt the resistor, something to watch out for when you replace it.

Also make sure this is not over fused as it should have burnt first unless it is a bad bridge rectifier. Just seems odd to have multiple problems like this at the same time.

I am just going from my personal experience. They wont burn unless a TIP locks on for awhile. For the OP his resistor is broken off and the relay will not work like this, maybe your resistors were overheated but not broken off.

Pull the fuse for the coil, the lone fuse with the pur/yel wire on both sides. This will keep the coil from burning while you test. Power on the game and check for DC volts on pin 1 of U-50 should be low. Then start a game and retest pin 1. Still should be low.

Yep!

This can be tested on your work bench, all you need a power supply from a computer and some idc connectors.

Red wire is 5 volts.
Black wire is ground.
Yellow wire is +12 volts.
Blue wire is -12 volts.
Green wire is a switch wire, connect green to black with a switch to turn on power.
But always double check as you power supply may differ.

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Then you wont need a switch.

I will need a pic of this.

Are you going to test sounds? If no then you only need 5 volts, +12 volts and ground connected to J17.

Loop the five volt wire around and connect it to two pins so you have enough current flow.

You can run two wires. Which ever is easiest.

Looks good to me, FIRE it up.

Right now the cpu is in attract mode and pin 1 .1 volts is good. Did the coil lock on in attract mode or when you started a game.

Then is sounds like the pre driver is bad, Q-76 is shorted. You can check this by checking voltage on R-102. It should be low voltage on both sides of the resistor. If you are getting 3-4 volts then the transistor is shorted.

Voltage tests always with power on. DC voltage black lead always grounded. Red lead is used for testing. Since you don't know which side of the resistor is tied to the tip you just check both.

1.32 volts is enough to turn on the tip. So replace the predriver. Then retest before you install it.

Give me voltage number after you replace the predriver.

Perfect. Now one last test before the install is disconnect the board and measure the resistance from ground to the metal tab of the tip for each of the solenoids. All should read high resistance. Then your safe to install it.

Rotate knob CC 9 clicks.

Go 6 clicks cw on this meter.

If the 11 was 1.1M ohm then that is good. And the 5-6 were .500-.600M that is fine for tip 122.

If the resistance is very high some meters bounce around a lot, but at least its not a low reading which would lock a coil on. I would say you have this board repaired now.