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TECH: DMD "Line Out" Stumper Question

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The_Black_Knight

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May 12, 2005, 12:06:46 AM5/12/05
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All,

I thought you might have some insight on this.
On my FT, I have one vertical line out on the DMD (second from the right),
consistently at all times.
The rest of the display is normal during all periods of operation.

After testing to confirm proper high voltages.......................

I have tested or replaced the following:
1) Replaced the DMD (Replaced for testing with a brand new display)
2) Replaced all ribbon cables to and from the DMD Display Board (with brand
new ones) and properly seated them.
3) Replaced DMD Display Controller Board (Replaced for testing with a brand
new board).
4) Performed a "Hard Reset" on the game
5) Removed, recleaned, and reseated the game rom on the CPU (Version L-4)

The problem was their before and did not change one bit after this stumper,
after I did a step by step change one thing at a time, as not to confuse or
convolute the troubleshooting.
I put the original boards back in because its not the problem. Tested
another DMD display, and it is also perfectly normal before and after by
using another game.

This makes me think, this is a trace or component issue off the CPU Board,
or maybe a bad game rom?
It has to be coming from upstream from the DMD Display Controller.
What could cause this anomaly?

--
"The_Black_Knight"

The Washington State Pinball Stronghold
"A Fortress Protecting the Silver Ball"

www.geocities.com/pinball_jack

a...@txpinball.com

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May 12, 2005, 12:18:13 AM5/12/05
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None of that will fix your problem. My guess is the problem is on your DMD
controller board. What you need to do, to get rid of that line is this:
Replace 6264 RAM chip at U24.

Best regards,
Adi
www.txpinball.com

"The_Black_Knight" <pinba...@earthlink.net> wrote in message
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The_Black_Knight

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May 12, 2005, 1:03:16 AM5/12/05
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Adi,

I already replaced the DMD controller board with a BRAND NEW board (Testing
#3), which I confirmed working status in another game beforehand. Then I
put in another confirmed working DMD Controller board as well, the line
remains missing. Its not on the DMD Controller Board, ribbon cables, or
display.

That is why I am getting stumped.
Thanks for the input, however.
I will find the problem, I always do.

--
"The_Black_Knight"

The Washington State Pinball Stronghold
"A Fortress Protecting the Silver Ball"

www.geocities.com/pinball_jack


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martin

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May 12, 2005, 2:07:53 AM5/12/05
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As a quick test, loosen the screws holding the DMD controller in place
so that it sags forward a bit. Turn the machine no, and jiggle the
board. This proceedure could expose an oddball short caused by the
mounting. Should also check the 5V supply at the controller board.

Can you switch out the WPC board? No need to change the ROM; just need
to see the display come up. You only have to connect power and the DMD
lines.

Trinity

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May 12, 2005, 2:34:37 AM5/12/05
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It could be on the sound board or the fliptronics board as well. I had a
WW that had a problem on the sound board that caused the display to show
some weird things. Replace them with know good ones then you can go to game
rom or cpu.

Trin
"martin" <martin....@gmail.com> wrote in message
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a...@txpinball.com

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May 12, 2005, 10:09:57 AM5/12/05
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Hmm... Then, that makes it murkier. On the back of the board, look for
shorts. Also, disconnect audio board, and fliptronics board from the ribbon
cable so you just have CPU and dmd board connected, see if that clears it. A
weird one, no doubt. Best of luck and keep us posted.

Adi
www.txpinball.com

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