FirePower Game Setting - I want Information!

Schematic for Master Display Board D8000 (IC version): Master Display Logic

Here you can see in a PDF the differences between discrete and UDN7180 IC version Master Display boards.
Be sure and page to the second page of the PDF for the transistor version. These are the assembly diagrams.

I also found a recommended link at ActionPinball.com on rebuilding HV Power Supplies for Williams Displays: WMS HV PSU
A whole list of technical articles are here: Action Pinball Tech

If you have the UD7180 version of the System 6 Master Display board, it may be worthwhile taking an easy step to prevent future problems:

The track is on the front left near the display glass. The top round pad in this picture is unused on the UDN7180 version but goes to the +100v supply at Pin 2 of 4J7. It appears that the pad shorted out to the ground track that goes around both of the round pads. Maybe due to humidity behind the backglass? Cutting the track to the top round pad like this, causes no problems for the displays on your game. But it may prevent a short which would blow up the HV section (+/- 100v) on your PSU, and may even damage your Master Display board as well.

*Warning* If you have the rarer DI-0512 Digit Driver ICs on your board, this trace is still needed, so don't cut it!

2. This can work when one I/O pair becomes faulty on your UDN-7180, and it's a System 4-6 Master Display Board (D8000).

An important discovery I came across when researching my solution is that pins 1 & 18 on the UDN7180 are *unused* by Williams for both of the 7180s on the D8000 Master Display Board! There is an extra I/O pair on the chip! The diagram looks like this:

**UDN7180 Pin Positions (vkk = -100v)**
IN	1	2	3	4	5	6	7	8	9 gnd
OUT	18	17	16	15	14	13	12	11	10 vkk

So the solution for me with a single segment gone on a UDN7180 was simple. Cut the faulty legs on the chip and jumper the lower number to pin 1 (Input) and the higher number to pin 18 (output). Good workaround. This may have been noticed and documented before, but I have never seen the information published and so thought it might help someone.

Sadly this will NOT work for a 8363 display driver board used in BK, and probably later boards as all the UDN7180 pins are in use. But you could buy an old display board for System 7 / 9 and rob the UDN7180 from there. Don't worry, there IS a replacement for the System7 (and Sys9) Display Driver board for aboput $75. With thanks to James Kohout of PinballPCB.com

The UDN7180 datasheet

The Firepower Display Wiring Harness for system 6 games. More Firepower (Williams System 6) documentation is here: FirepowerPinball.com
and the Black Knight Display Wiring Harness for later system 7 games. More Black Knight (Williams System 7) documentation is here: BlackKinghtPinball.com
More on why I made them and the game ROM strobe tables when I have more time for documentation...
Hint: I got Firepower, Alien Poker both playing in one cabinet with only the playfield and backglass swap. And moving a couple of ROM jumpers. Gameroom space is critical for me.
Does my speech board mod start to make more sense?