Hi All, On my Willams MM - Original, I turned it on and noticed that the DMD was wavering and all the middle was out and around the edges was wavering an lit. The more I have had it on troubleshooting it, Now the DMD is totally out.

Game has worked flawlessly for 11-12 years I've owned it.

Here is what I've checked:
1) I put in a spare DMD that is used but worked last time I used it but had one or two dots weak. Nothing it is totally dark
2) All 6 LED Power Driver Voltages LED's are lit signifying I have all my voltages
3) LED 501 is flashing at it normal rate for the +5VDC
4) All 3 CPU LED's are working as manual indicates they should
5) I tested AV Board J605, pin 1 & 2 and I am getting 87.6 VAC
6) At J604, with the DMD connector unplugged, here are my readings:
Pin 1 = -1.7 VDC
Pin 2 = -1.3 VDC
Pin 6 = 0 VDC
Pin 7 = 0 VDC
Pin 8 = 0 VDC

At the DMD with connector connected:
Pin 1 = -1.7 VDC
Pin 2 = -1.3 VDC
Pin 6 = 0.08 VDC
Pin 7 = 0.1 VDC
Pin 8 = 0.1 VDC

What is my problem, anything else I need to check?
Trying to figure out where my problem is.

Thanks for any help!

Also the whole game plays normally and all other functions are normal

Thanks DumbAss, yes i had checked those two fuses in circuit but i wll definitely check them out of circuit.

On the voltages, I clearly checked them in DC Voltage, the only AC check I did was on pin 1 & 2 of J605. I thought that was weird to as the LED on AV Board that flashes slowly signifies the +5VDC

I'll check tonight and report back.

Thanks for the help, greatly appreciated.

Also the answer your question, I had the black lead clamped onto the ground strap on the bottom left of corner inside backbox beside the grounding screw/lug and then used only the red lead of Voltmeter. I am using a premium meter as I have a Fluke 87

Hi Guys, I want this fixed ASAP, I ran home and rechecked this again, here are my findings:

I removed all fuses on the AV Board and all checked good

I did a recheck and secured a better ground and got more accurate readings:

I tested AV Board at J605, pin 1 & 2 and I am getting 86.1 VAC

At J604, with the DMD connector unplugged, here are my readings:
Pin 1 = -116 VDC
Pin 2 = -91 VDC
Pin 6 = 5.03 VDC
Pin 7 = 11.66 VDC
Pin 8 = 2.2 VDC

At J604, with the DMD connector plugged connected to DMD, here are my readings:
Pin 1 = -116 VDC
Pin 2 = -104.9 VDC
Pin 6 = 5.03 VDC
Pin 7 = 11.66 VDC
Pin 8 = .63 VDC

At the DMD with connector connected:
Pin 1 = -117 VDC
Pin 2 = -105 VDC
Pin 6 = 5.0 VDC
Pin 7 = 11.66 VDC
Pin 8 = 0.6 VDC

Next Steps?

Thanks, yeah from what I reading that's what I am thinking too!

Hi guys, thanks all you prompt for the feedback. I am getting someone who knows board work well to go through it all.

FYI..... I did try a known good DMD in the game and nothing, dead, it's the board for sure.