Hey all,
I'm very technically inclined, yet pinball machines have always scared me... Haha.
I recently bought a 1995 Gottlieb Big Hurt machine that was in awesome shape, except 2 coils were removed. I was afraid that it may have been a driver board issue, but I wanted to snag the machine anyhow... Even without the 2 coils, it's great fun...
But, I wanted to start fixing it piece by piece...
I installed a new Kicker coil, and it locked on as soon as the game started....that told me it was most likely a board issue...
So, Last night, I sucked it up, and I gave myself a crash course in transistor testing and diagnosing ...
Good news, it turns out that Transistor Q4 (the one that controls the faulty kicker coil) is bad. I tested it in diode mode, and it was only registering 0.2 on both top and bottom leg. A proper diode should register between 0.4 and 0.6 on the bottom leg and OL on the top leg. Definitely a bad transistor.
Q12 is also showing bad as its showing continuity when any tests are done... Q12, By no surprise, is the transistor that's linked to the only other coil that was missing from the game... The center ramp lifter. BINGO!
Now I know what to fix, and it will only cost a few pennies!
Yay for me!
Just Sharing my experience and excitement!