Hello pinsiders.

I picked up a firepower 2 last week and the previous owner had unhooked the driver wire for the lower left pop bumper because it stayed locked on. I'm still green around here, but this is how far I have made it. I have diagnosed all the way back to the driver board special solenoid 19 along with solenoid switch 19. I have removed the connectors from the driver board that are sending and receiving inputs from the playfield.

Still on the driver board connector 2J12, pin 3 Q6 my dmm is finding ground. I have checked the transistor Q6 and the test checks out. I visually cannot see anything burnt or mis-soldered. Where should I check next? The manual does not show past solenoid 16 drive on the driver board diagram.

Thanks Eric

Thank you. I need a higher resolution diagram. I cannot read the connector labels on mine. I just saw soleniod 3 and kept moving.

I will get back with you on the diagnosis. Since I tried re-seating the IC-6 and accidentally bent and broke a leg off the chip. So waiting for a new one to arrive.

I am completely confused now. After replacing ic6 with a new chip "correctly orientated", The game will not start at all. The main board boots according to the single digit display on the CPU board. But with two balls installed the start button does nothing.

I have been through solenoid test and all the coils are hitting, minus the original pop bumper which is unhooked.

How should I approach this new found problem?

I did the switch test with both balls removed and both balls inserted. The switches are registering normally.

There are only two trough switches and they are both depressed with two balls inserted. I saw in the manual it calls for three balls but firepower 2 only has a two ball multiball. I tried the test with three and the return has a hard time loading the third into storage. I think it is only a two ball game.

I woke up with an idea. So turned on the game a loaded 2 credits on the machine and it started a game.

For some reason the free play setting was reset to factory credit play.

Today a new transistor arrived for Q6 so I replaced it and the coil still locks on. The coil stays disengaged until I press the credit button to start the game and it locks on immediately.

I will pick up a logic probe today.

The the only component left is the predriver.

It has a new coil and diode. Since the other burned and swelled. Thanks to the previous owner.

I just tested on IC6 12 and 13 and they test as follows.

Attract mode: 12 low level false condition
13 high level true condition

After game start they test exactly the same conditions as in attract mode.

I have moved to IC 8 it tests

attract Game on
4-false null
5- false false
6-true false
14-true true

I have continuity between the orange/black and the ground. So is it this capacitor?

1556832263083185790013 (resized).jpg

Never mind it is still finding continuity with it clipped. I will keep searching backwards

With the game in attract mode and game started. R-3 is only getting 5 volts on one side of the resister. The otherside is not receiving power. Is this correct?

C-3 has continuity to ground. Across C-3 it has .4 ohms, that's basically open right?

Sorry I meant short. With 2J-13 disconnected pin 12 is sill reading low. Sounds like its time to replace C-3? Or is there more testing I need to do?

R-3 has .25 K Ohms
I lifted a leg on C-3 and and it is showing open

I retested pin 12 with the leg lifted and it is still reading low.

Success, here is what I have just found. The screw in the upper left hand mounting position for the driver board some how was grounding the back of the c3 and r3 section of the board after taking the screw out while testing I was able to press the board back and forth create the locked coil symptom. Wow what a bogger. Thank you so mouch Grumpy for getting me through this.

It is a factory board. I'm wondering if after the boards were serviced "according to previous owner" the Interconnect pin replacement spread the boards a little further apart and the mounting locations didn't line up and the boards were flexed into position causing the ground.

I sure will. I want to reposition the mounting brackets to take the pressure off the boards. Its just hanging there at the moment.

Here is what was happening. This screw was pushing down on the back of the board when tightened up to the back box mounting brackets.

15572770797291872370543 (resized).jpg

1557277202892432895903 (resized).jpg

I'm going to remove the plastic bracket off the board. So it doesn't push on the board. The board set is still mounted by the original 8 screws. Thanks again Grumpy.