Williams firepower pinball display problem

[Hammerhead]

I have a Williams Firepower pinball machine; I have been going over it following the repair guides on Marvin’s repair site. I got the CPU and driver board working and the game boots up and you can play, but the displays are giving me problems. I have 2 versions of the master display board, the D-8000 (with the UDN7180A chips) and also the D-8168, which is the transistor version. The D-8168 board doesn’t seem to work at all when installed, I get an orange glow in the corner of the displays but that’s all. I have checked all the transistors, and they checked out as ok. With the D-8000 version, the displays work, but some of the digits are missing, (on all the displays) and they are dim, like they are fading, and the credit, ball in play display glass on the master board doesn’t light up at all. When I put the machine in test mode with the coin door open and run through the diagnostic program, all the displays work (still a little dim but ok to see) and the coin and credit display on the master display board works and lights up fine. I have checked all the resistors and replaced 3 that were bad, but it didn’t make a difference. Unfortunately Marvin’s site doesn’t go in-depth with repairing the displays. Any suggestions on how to fix the problem, or even where to start would be appreciated; I would like to repair them if possible. Sorry to be long winded, I’m just trying to give as much info as possible. Thanks.

[leapinlew]

I can't help you, but I just wanted to say that is my favorite pinball game. Awesome machine...

[Hammerhead]

LOL Yea its killing me that it works but I can't play because of the display problem! A little more info, I checked the blanking signal and it is fine, and I have +97, and -98 volts at the plug to the master display board, and have swaped in a few different extra score displays that I have, and still get the same results.

[ChadTower]

Replace the header pins and connector pins on the CPU for the two harnesses that drive the display data.  They are very commonly dead or mostly dead by now on Sys6-7 games.  Very flaky.  Even if it's not the complete cause it needs to be done, guaranteed.  IIRC they're up at the top right of the CPU.

[Hammerhead]

Thanks Chad, I'll have to order some pins and connectors and hopefully it will solve the problem!

[ChadTower]

You probably don't have to replace the connector itself, just pull the pins and put new ones in.  Trifurcon pins if you can, they are much more reliable and don't cost any more.

[Hammerhead]

OK thanks, my machine has those connecters where the wire isn't crimped in, just pushed in (self splicing) I think they are called IDC housing or something, so I think I will have to order new housings and pins to go with it.

[ChadTower]

Good point.  I was remembering those machines as having better connectors, but I just looked in my two Sys7 pins and they are both IDC.  Replace the connectors.