Williams High Speed (Williams, 1986) (Williams System 11) problem

[WiseGuy]

I am having a problem with my High Speed machine. After normal start-up and either playing or in attract mode, 4 of the lamp matrix columns (1, 2, 5, 6) and the upper half of the displays will start to fade, then go out completely. After a while, the CPU board relay (K1) will start to hum. If the machine is turned off for a while, everything goes back to normal, and the cycle starts over when turned on.

Everything else works fine, and I have tried swapping U41 and U42, and U15 and U24, but nothing changes.

My question - what is common between the upper half of the displays and certain columns of the lamp matrix that could cause this problem? Could it just be the CPU board replay (K1)?

Any help is appreciated

 

[spalmer]

Wow that is strange. Replay K1 is to enable the flippers, that is not going to issue. Educated guess without lookingat the machine is going to be connectors 3j4 and/or 3j5 on the power supply board. If these connectors are heating up, it could cause some strange behavior. Try wiggling these connectors when the problem starts and see if it makes any difference.

 

[WiseGuy]

Thanks for posting spalmer. I tried wiggling these and all other connectors on both the power and CPU boards with no change. I then re-soldered all the power board connectors just to be sure. Tried again, and still the same thing.

I then disconnected MPU j6 and j7 (lamp matrix connectors) and turned on the machine. After a while the top half of the displays dimmed and went away. Then I reconnected j6 and j7, and disconnected j21 (display) and turned on the machine. Once again, after a while the matrix columns 1, 2, 5, 6 dimmed and when out. This leads me to believe there is something on the CPU board that is just wrong.

But I have no clue what would connect them.

 

[spalmer]

Here is what they all have in common, (proximity to the battery holder). Check that board really close for battery damage around (U41,U42,U54 and U51). See the attached picture. U41 and U42 control the displays, U51 controls the solenoids (ie, flipper relay) and U54 the lamp matrix. It could be that there was some battery damage at one point in time that is causing the problem. Can you send me some good pictures of both sides of that board. I have 2 system 11 machines of my own. If you can not get this thing working, I would be willing to take a look at the board if you are willing to ship it. Mine are an 11a and 11c revision but I can still test the lamps and displays with them.:)

 

[WiseGuy]

Thanks for the info and the offer. When I obtained the machine, there had been acid damage, and someone prior had made repairs. I checked the repairs before, and didn't find anything that looked like an issue.

With your info, I have re-checked, and actually removed the U41 and U42 sockets, and underneath, some of the repairs look questionable. I'm going to complete the repair, and look at the other components in the area. Since both the display and lamp matrix are affected, my thinking is still that the problem resides in something that is common to both - either component or circuit board.

Thanks again, and I'm still having fun, so its worth it. Depending on where this leads, I may take you up on your kind check-out offer.

 

[spalmer]

Had any luck??