I picked up a project Firepower McPin54 outside Canton, OH on New Year's Eve. Scott is a great guy with an amazing collection, along with a handful of project pins always ongoing in his garage! Do not hesitate to do business with him. I knew exactly what I was getting into when I picked this up and the price was right.

Anyways, I knew I had a non-booting game with a great playfield, which to me was worth the challenge or trying to preserve all original boards.

When I powered up the game, I had GI, flippers active (that's bizarre), and nothing further. I re-checked the connectors and realized there's a rogue 3 pin molex connector that goes under the playfield, which added attract mode insert lights to the lack of activity.

1.) One look at the MPU and I knew I was in trouble. The batteries were corroded, one so severely that green corrosion covered the entire battery and was unreadable. Because the battery holder is in the right bottom corner of the MPU, the damage to the MPU was miniminal, affecting the adjacent 74LS02 and the .01uF capacitor. I cut these out, soaked the board in vinegar, steel brushed away any remaining corrosion, rinse, dry and replaced the components.

2.) The driver board, being below the MPU was in far worse shape. The alkaline damage was so severe that when I removed the old TIP42 lamp matrix transistors and shitty 3W 27ohm resistors, the typical burned PCB underneath actually had the primary traces completely eroded and sitting free on top of the partially desolved PCB. A number of chip legs were clearly corroded. My friend offered to sell me a driver board for $80 (an excellent deal), but I wanted a challenge. Again, a prolonged vinegar bath, brush, vinegar again, brush, rinse, air gun dry and waited a day. I did Vid's bullet proofing and replaced the TIP 42s with IRF9Z34N MOSFETs, the 27 ohm resistors with 0 ohm resistors, and a couple 2N4401 predrivers on the board that had legs touching and I wasn't sure of their health. To my amazement, I had continuity everywhere and glued down the floating copper traces.

3.) I replaced the 40 pin interconnect on both the female and male side as many of the springs were shot.

4.) Lastly, I checked to make sure I didn't have any of those junk scanbe sockets (nope, whew!), reflowed any cold solder joints, and mounted a new off-board battery pack.

I plugged everything in at this point and prayed. Good news -- nothing bad happened. Bad news -- I was still in the same state as when I got the game. When I pressed the diagnostic switch I got 2 flashes of both LEDs and then nothing. This tells me that I'm on the right track, but the CPU isn't booting.

5.) I grabbed the multi-meter and checked the 5v test point on the MPU and had 4.44V. Note, the PCBs are not labeled, and in a few cases pin 1 (which is labeled) is wrong when compared to the schematics. Trust the schematics. 4.44V isn't obviously enough, so onto the power supply. I had planned on doing Vid's bullet proof section of the power supply, but hoped I had a working game first. Nope! One look at the 12000uF big filter cap and I saw a pile of hardened leakage at the top. No Bueno. I spent the afternoon doing the following:
a .) Replaced the 12000 uF cap.
b.) Replaced the 100 uF/100V cap.
c.) Replaced the 100 uf/160V caps.
d.) Replaced big D7/D8 diodes with 6A4s
e.) Replaced Z2/Z4 with lower voltage zeners, as well as R1, R2, R4, R5 to preserve the life of the displays -- which at this point showed no signs of life, so I had no idea if they were good or bad.
Reflowed all cold solder joints along the interconnect pins.
I didn't replace all the fuse holders because they looked relatively new, but I stupidly did not check the fuse values.

I reconnected everything back together and viola! I had a booting machine and working displays!! I started a game and immediately noticed a few things. I had no working solenoids (other than flippers) and I had sounds but no voice.

6.) I checked the sound board which has a sound/voice pot. I noticed it had been turned all the way to sound. Adjusting it back to center restored the proper sound and voices. I then adjusted the long pot on the left side of the cabinet to adjust the volume.

7.) I checked the solenoid fuse (2.5A) and it was obviously blown. I should have checked these while rebuilding the power supply, and for that I'm a dumbass. Replaced the fuse and solenoids work!

So now I have a 99% working game. The only remaining issue is that the upper right saucer holds the ball, counts points indefinitely, and won't eject the ball. If its lock is lit, it does hold the ball and eject a new one into the shooter lane which seems correct. Any ideas?

OK, I finally figured out *how* to step through the diagnostics. I'm not sure which test is the right saucer (the one I'm talking about is the one to the right of the pop bumpers), but no it does not fire. It appears to be the only one not firing. I'm not seeing anything obvious like a wire off the coil.

Yeh, I need to print out a copy of the schematics as the game didn't come with one. This should be pretty easy to troubleshoot now, especially since it's isolated. Thanks for your help!

Sigh. Fix one thing, break something else. Coil tested fine. Found the 2N4401 predriver had the center leg loose from solder joint. Replaced it and the TIP120 with a TIP102 anyways. Saucer works.

Now it won't start a game. Found one of the 3 trough switches not registering. Then found the entire green/violet column 7 shorted, which I know I did when I had the playfield resting on the lockdown bar like a dumbass.

Everything is working perfectly. Column 7 issue stopped after I reseated the switch column header. Wasnt seated properly. After that, Trough switch #2 wasn't closing even with the weight of the ball...tough to test... so the game wouldn't start. Adjusted with my leaf switch tool and fixed.

Plays amazingly well!

LaPorta, the leg crossing of transistor replacement only occurs in a very specific location due to the part replacement. this was done correctly on the power supply rebuild.

My first game clearly showed that I had it set up wayyyy too easy with a 1.8M ball 1. Of course I won last night's tourney so my level of play is getting stronger. Need to jack up the back legs!