My Ripley's Driver Board is going spastic. Most of the time when I turn it on, the controlled lamps and solenoids all start flashing/energizing in a pulsing pattern. Once in a while it starts up fine and then goes spastic about 5 minutes later. It seems like it is the watchdog chip, but it does it with 2 different driver boards.

Any help is appreciated.

Thanks.

There is a watchdog chip on the driver board (U210 it is a DS1232). I put the logic probe on it and the pulsing of the lights/solenoids was lock step with it.

I was hoping somebody could tell me where the signal that comes off the CPU board to tickle the WD comes from. Trying to unravel the schematics is painful when they are chopped up in the manual so badly and practically everything dives into a buss and comes out who knows where.

It was blowing 1 or 2 fuses, but I put that down to having all of the solenoids pulling at the same time. I finally left the coin door open so the solenoids weren't firing all the time.

Thanks.

Thanks for the help/suggestions. I haven't had a chance to look at it since the last post. I am hoping to get some quality time tonight.

For anybody that is keeping score, there are 2 watchdog chips. One on the CPU board (U413 also a DS1232). The CPU watchdog drives the driver board watchdog via pin 13 of the ribbon cable. This is driven via transistor Q10.

Now that I have the path worked out, I just need to run the logic probe over it and see who is not doing their job correctly. If it were only that simple....

I have checked and the batteries were not leaking, I have reseated the ribbon cable several times, the CPU appears to be booting and occasionally it will stay working for several minutes before the watchdog starts spazing out.

After poking around with the logic probe, I found a trace on the D3 data line up near U213 that had a hairline crack in it and a broken socket pin in the U213 socket. Fixed both and it seems to boot and continue to play. Next up is why it is kicking 2 balls out.

Apparently there was some slight battery damage at some point before I got it. I replaced the CMOS with NVRAM a long time ago so I wouldn't have to deal with those kinds of issues. Grrrrrr!

Last issue resolved. Put the game is switch test. Fiddled around for a while and then popped all 5 balls out to raise the playfield. WTF. RBION is only a 4 ball game. Somebody was helpful and popped in the spare ball I keep in the coin box for those times when it "loses" a ball mysteriously.

4 balls in and it plays just fine now.