Hiyas!

Your problem isn't related to grounding your power outlet (that's a good idea, but it doesn't cause this).

For some reason your computer isn't coming on.

The most likely cause of this is unfortunately battery acid damage on the main computer board.

It could be a fuse!

So, inside your front coin door, on a little hook there is likely a different key. This key opens the lock in the backglass area.

If you look at the backbox, there is the dot matrix display, then above that is the backglass, in the center facing downward in the top of the wood framed backbox is the lock for the backglass.

Insert the key, turn it. Then run your fingers down the glass until you find the 'lift rail' plastic. Get your fingers under this little 'lip' of plastic, lift upward (less than an inch), and the bottom of the glass should clear it's track. Then pull the bottom toward you an inch or so, and lower the glass out of the top track. Set the backglass to the side.

Inside are three boards, a small one in the upper left, and two big ones on the right. In the upper right corner are some flashlight batteries. We are looking for evidence of battery acid, or corrosion. Let us know what you find.

Best answer is no battery acid problems!

On the bottom big board, there are lots of fuses.

With the power on and the front door closed, all four of the LED's in the middle should be on. Let us know if you don't have one of those LEDs on.

A lot of times this is a fuse issue, so if we know which LED isn't coming on, we can help figure out which fuse.

This could be a lot of things, so if you suspect something, take a hires picture of what you see and post it here.

Get back with us and I'm sure we can help you!

Thanks!

Had this issue with a friend's AFM ...
checked everything and then lastly the LEDs ... the Bulbs were all fried!

Silly nitpick: there's no "battery acid". Leaky batteries in pins are pretty much always alkaline batteries, and the electrolyte is (of course) alkaline, i.e. pH higher than 7 (acid is pH lower than 7). The only commonly available battery with acid in it is lead-acid battery, the kind you find in motor vehicles to provide 12V for starting and running accessories when the engine's off. I've never heard of anyone putting a lead-acid battery into a pinball machine.

This is of course mostly a pointless matter of semantics to worry about, but I mention it because it could be someone might come across the post, think that actual acid is involved, and attempt to neutralize the acid with some kind of alkaline substance (e.g. baking soda), which would just make the problem worse. There's a small possibility that making sure we're accurate about terminology could matter.

pete_d... I agree, and I don't think it's nitpicking. I usually write 'battery acid (alkaline)', I don't know why I didn't this time.

Kow86,

All machines come with a history.

The capacitors next to the audio output look as though they failed, leaked electrolyte (looks like corrosion on the top of the board by the green caps), so a previous tech replaced the caps, and where the traces were compromised they ran that little piece of black wire.

You would think that there is enough clearance that the wire wouldn't have shorted to the backplane, but maybe it did. A little piece of electrical tape would probably keep things from shorting out.

The big problem is figuring out if your computer board is actually working.

The two LED's on your CPU (Top board) should be on.

If you have a meter, CN2 (bottom left of the top (CPU) board) should have +12v, -12v, Ground and +5v on the pins that are marked on the board.

If you've got good power in, then it's a matter of why does the CPU not seem to be running, and that starts getting into board repair.

Let us know what you find.