Hi Smart People,

I have a WPC driver board I'm trying to get working again with not much luck. The problem is that the driver board received 50 volt solenoid power to the 5v logic line. I first found that the LM323 was bad. I changed that out and I now have a driver board with good 5 volts being produced. All test point voltages test perfect on the driver board. When the driver board is installed in a known working game, the game will semi boot up. What I mean by this is that the CPU seems to come alive with led activity, the game gives out it's start up bong sound. There is no attract mod lighting, no GI lighting, no flippers, but the game accepts a coin and makes noise while doing it. When touching a meter to the 5 volt line and ground it makes an audible beep....this can't be good?! So I'm thinking I have some sort of short in a 5 volt component that must have been caused by the 50 volt short finding ground? And this is why the driver board won't do anything as it's not receiving info from the cpu? If so, how the heck do I find the culprit that's grounded out without shot gunning things? I have a meter and a logic probe but I'm at the end of my skill set and could use some help. Any help much appreciated.

Thanks!

I don't mind sending the board out for repair if someone is accepting new work and doesn't mind working on this. In the mean time, I would like to see if I could learn something new and fix my own mistakes since this is my hobby. I greatly appreciate all and any help in this learning process.

I did a quick transistor check from ground to the metal jacket and everyone seems ok.

I'm poking around with a meter comparing similar ICs seeing if I can find a leg connected to ground that shouldn't be. There was no magic smoke released during "the incident". So there are no obvious components to change out. I was hoping someone might be able to help me see if the data lines are working at all. Not sure what I should be looking for there other than "activity" with the logic probe. Things can't be all that bad if I have proper voltages at all my test points....that's the problem most of the time.

The CPU is indeed fried as well. I have an extra CPU from a Demo man. The fried one is from Fish Tales. I think Demo man is the security version of CPU but should work in the Fish Tales? I'll have to read up on that. So that may be an option if I can't fix the original.

What a great learning experience I have created for myself. Yay!

Thanks for the help guys. It sounds like I really screwed up and have a real difficult mess on my hands now....I was trying to stay positive and optimistic but sounds like I created a shit real storm for myself. Doh!

Chris, thank you for your insight and detailed explanation. Sounds like I was on the right track but this is way more complex than hobbyist level. I hate to ruin this board anymore by replacing every IC as it was a nice original till I got to it. Chris, if you are open to taking on this challenge I'll certainly send it your way. I'll send you a PM explaining what exactly I did so maybe it will help in the repair.

Thanks for the great advice people. Now, what else can I break this morning....hmmmm....