So I had my WMS IJ completely torn apart (playfield removed all connections in the backbox removed) to do all new decals. Finally got it put back together and fired it up......no display, no sound, idol just spins and a few various lights on.....that was it.

Narrowed my troubleshooting down to the CPU board. When I turned it on LED's D19 & D20 are off and D21 is lit. So I have power but the CPU is not booting. Unplugged everything but the power (J210)....better, D19 lights for a few seconds and then goes off as D20 starts blinking (D21 remains on). Looks like a proper boot sequence.

Plug the "power/driver" ribbon cable in (J211) and fire up....still good. Plug in J202 (I/O Sound ribbon)....still good, plug in J201 (I/O Extended)......no go. I do power off and back on for each test.

I noticed when I unpluged J201 leaving J202 still connected that it would NOT boot. So, if I plugged in one of the top ribbon cables (either one) it still booted. As soon as I plugged in the other it will not boot and won't boot properly until I unplug both.

I'm thinking it's the TTL circuits just below the top ribbons.....U1-U3. But is it all three? Do I need to replace or just reflow? Thanks.

I've triple checked this possability. It boots correctly until I plug in the top ribbons....then it does not boot at all. I've (carefully) run this test several times.

???

IJ boots....until I connect the top ribbon cables....which is why I'm thinking it's the TTL Circuits U1-U3. Really If I want to test the game GPU shouldn't I stick IJ into STTNG? I really don't think it's the game GPU though....since it boots without the top ribbons attached. If it was bad it should never boot.

This has been double checked on all ribbon cables. I'll try swapping the boards.

I swapped the boards. STTNG did not boot in IJ and IJ did boot in STTNG.....so my first thought was "bad ribbon cable/s".

Swapped the two top ribbon cables from STTNG into IJ.......nope.....damn! It appears to be an issue with J202, which is the ribbon cable that plugs into four separate boards. So now I need to find which connection is the weak link.....but then what?

The IJ board did boot in STTNG.

Here's where I'm at. Plugged J202 into the CPU board and the fliptronic board....check. Added the sound board, check. Added the display board, no boot.

Now I'm really confused. Swapped the display board out of STTNG and still no boot? If I unplug J601 (the top ribbon cable) from the display board it then shows a proper boot sequence on the CPU board. Plug in J601 on the display board and D19 and D21 light and stay lit. D20 never lights (or blinks). Scratches head.

Stupid is as stupid does.....

J606 (the power to the display board) the cable was completely missing! Found it sitting off to the side (connected to cables that are no longer used becasue of the color DMD).

So I seperated it and plugged it back in an wah lah!.....back in business.....well almost. Fired up a game and everything appeared fine until I hit the flipper switches......nothing dead. They show up in test mode but do nothing in a game. So now I get to figure that out.

Back to 100%. Another power cable issue with the flippers easily fixed.

20160517_201608_(resized).jpg