DMD Issues

G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Getting a little frustrated here, hopefully someone can point me in the
right direction.... After googling and Clay's site, I still am puzzled.
I have a known working DMD that I cannot get to work on my LW3. I
checked all voltages....All are in spec (including the +5 on the dmd
controller board and all the high voltages at the dmd itself)all
voltages are good. The DMD is good, all the ribbon cables are seated
and reseated correctly, verified new working roms are seated correctly,
and new bridge rectifiers were installed. I am getting the CPU
controlled lights, so I would assume that the BR related to this is
working correctly. The display appears completely dead when the machine
turns on, no matter how many times I reseat the cables, check
connections, etc....When I turn the machine off, the DMD shows bright
garbled images for a split second, then turns off as the machine powers
down. I can repeat this repeatedly, with the same result every
time....TIA for any thoughts/advice....Tim
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Are you SURE your voltages are CORRECT? Remember, the display needs 12
volts and it gets that from the difference between the +100 and -100
volts. For example, if your +100v is +120v then your -100v needs to be
-108 volts. The difference will be 12 volts and your display should then
work.

Tim N. wrote:
> Getting a little frustrated here, hopefully someone can point me in the
> right direction.... After googling and Clay's site, I still am puzzled.
> I have a known working DMD that I cannot get to work on my LW3. I
> checked all voltages....All are in spec (including the +5 on the dmd
> controller board and all the high voltages at the dmd itself)all
> voltages are good. The DMD is good, all the ribbon cables are seated
> and reseated correctly, verified new working roms are seated correctly,
> and new bridge rectifiers were installed. I am getting the CPU
> controlled lights, so I would assume that the BR related to this is
> working correctly. The display appears completely dead when the machine
> turns on, no matter how many times I reseat the cables, check
> connections, etc....When I turn the machine off, the DMD shows bright
> garbled images for a split second, then turns off as the machine powers
> down. I can repeat this repeatedly, with the same result every
> time....TIA for any thoughts/advice....Tim
>

--
Cliffy - CARGPB2
A passion for pinball!
http://www.passionforpinball.com
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

I know this is the case for my WH20, but is it the same for my LW3? I
was measuring voltages according to clays site and my schematics, there
was a -110 going to the dmd but there is no +110(100?) going to the
DMD? aybe if I write the listed voltages (schematics)and the actual
voltages according to my multimeter....

To the dmd glass=
-110= -110.6
-98= -101.2
+5= 4.89
+12= 11.87
+68= 68.6

To the dmd board=
+5= 4.9

Is there somewhere else I should be checking voltage?

Thanks again...Tim
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Okay....I was thinking along of the lines of a bad DMD controller
board...But here is the other thing I have done... Originally this
board had the two display eproms in place. I bought a complete rom set
from John Wart Jr. as I dont have an EPROM programmer. I snipped the
R11 resistor as stated on Clays site and then updated to the single rom
from John. My guess is it may be a bad board, only for the fact that
both the single EPROM and dual EPROM setup gave me the exact same
result. Is there anywhere that describes how to repair one of these dmd
boards for DE? I replaced a high voltage section on my WH20 without any
problems, but how different is this DMD controller? If it is not
documented anywhere, I probably cannot tackle it without some help. I
can read scematics,pictures and written instructions fine, but trying
to troubleshoot these boards without any reference is a bit tough. Are
these boards easy to find? Are they expensive? This is one board I dont
see around RGP, EPay, Mr. Pinball, that often.... I would prefer to
rebuild this thing if it is indeed bad.......Thanks again toeveryone
with their help.....Tim


Cody.....One of which should be positive? My positives are the 5,12,
and 68... My negatives are 110 and 98......
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Your -110 reading should be +110. Then you will have the 12 volts
needed. Are you sure you're hooking up your leads correctly? You may be
reading the polarity backwards on that 110 volt line.

Tim N. wrote:
> I know this is the case for my WH20, but is it the same for my LW3? I
> was measuring voltages according to clays site and my schematics, there
> was a -110 going to the dmd but there is no +110(100?) going to the
> DMD? aybe if I write the listed voltages (schematics)and the actual
> voltages according to my multimeter....
>
> To the dmd glass=
> -110= -110.6
> -98= -101.2
> +5= 4.89
> +12= 11.87
> +68= 68.6
>
> To the dmd board=
> +5= 4.9
>
> Is there somewhere else I should be checking voltage?
>
> Thanks again...Tim
>

--
Cliffy - CARGPB2
A passion for pinball!
http://www.passionforpinball.com
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

You can measure the 12v difference by putting your multimeter leads on
the two negative voltages, polarity not important. It should show 12v
more or less.

Your meter will do this because it detects the difference in the two
voltages. That way you don't have to do the math.
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Tim,

One of these should be a positive (+) voltage.

> -110= -110.6
> -98= -101.2



"Tim N." <nobliti@yahoo.com> wrote in message
news:1120701217.536417.59630@g47g2000cwa.googlegroups.com...
> I know this is the case for my WH20, but is it the same for my LW3? I
> was measuring voltages according to clays site and my schematics, there
> was a -110 going to the dmd but there is no +110(100?) going to the
> DMD? aybe if I write the listed voltages (schematics)and the actual
> voltages according to my multimeter....
>
> To the dmd glass=
> -110= -110.6
> -98= -101.2
> +5= 4.89
> +12= 11.87
> +68= 68.6
>
> To the dmd board=
> +5= 4.9
>
> Is there somewhere else I should be checking voltage?
>
> Thanks again...Tim
>
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

If you burned the eproms for the display board, I will bet it is that. I
have run into that problem myself, erased reburn and nothing, then switch to
a 27C040 and it works, for some reason some data east games don't like
274001 etc.. Or your image is split and on 2megs and same problem, or
jumper is incorrect on display board, for 2 or 4 meg. When I turned game
off same thing bright garbled line goes across display.

Trin
"Tim N." <nobliti@yahoo.com> wrote in message
news:1120701217.536417.59630@g47g2000cwa.googlegroups.com...
>I know this is the case for my WH20, but is it the same for my LW3? I
> was measuring voltages according to clays site and my schematics, there
> was a -110 going to the dmd but there is no +110(100?) going to the
> DMD? aybe if I write the listed voltages (schematics)and the actual
> voltages according to my multimeter....
>
> To the dmd glass=
> -110= -110.6
> -98= -101.2
> +5= 4.89
> +12= 11.87
> +68= 68.6
>
> To the dmd board=
> +5= 4.9
>
> Is there somewhere else I should be checking voltage?
>
> Thanks again...Tim
>
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

You probably have a problem with the
DMD driver board. Either that, or a
ribbon cable _still_incorrect.

--
Fred
TX
CARGPB#8
******************



"Tim N." <nobliti@yahoo.com> wrote in message news:1120696767.738615.259590@z14g2000cwz.googlegroups.com...
> Getting a little frustrated here, hopefully someone can point me in the
> right direction.... After googling and Clay's site, I still am puzzled.
> I have a known working DMD that I cannot get to work on my LW3. I
> checked all voltages....All are in spec (including the +5 on the dmd
> controller board and all the high voltages at the dmd itself)all
> voltages are good. The DMD is good, all the ribbon cables are seated
> and reseated correctly, verified new working roms are seated correctly,
> and new bridge rectifiers were installed. I am getting the CPU
> controlled lights, so I would assume that the BR related to this is
> working correctly. The display appears completely dead when the machine
> turns on, no matter how many times I reseat the cables, check
> connections, etc....When I turn the machine off, the DMD shows bright
> garbled images for a split second, then turns off as the machine powers
> down. I can repeat this repeatedly, with the same result every
> time....TIA for any thoughts/advice....Tim
>
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

if it is the display driver board send it out. I never hear of any one
fixing them, they usually run like tanks, I had two broken ones, took a week
and half to track down chips for board, got a scope took readings from a
good one, took notes. Put in bad one took readings, signal bad on suspect
chip, go back to next chip, signal bad, chip before that one looks good,
replace chip causing problem same thing, short story, replaced half the
chips on board finally runs. Damn scope did not help much. Two weeks to
fix one board not sure which was bad, called stern for help they told me
they just buy new ones, did give some tips on what usually fails but it was
none of them.

Trin
"Rex Mitchell" <twig@molalla.net> wrote in message
news:1120710722.810545.40180@g14g2000cwa.googlegroups.com...
> You can measure the 12v difference by putting your multimeter leads on
> the two negative voltages, polarity not important. It should show 12v
> more or less.
>
> Your meter will do this because it detects the difference in the two
> voltages. That way you don't have to do the math.
>
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Your DMD controller is probably dead (the board on the back of the speaker
panel). I've had that happen on a DE before.. There's no way to know for
sure other than swapping it with a known good one.

Mike


"Tim N." <nobliti@yahoo.com> wrote in message
news:1120701217.536417.59630@g47g2000cwa.googlegroups.com...
>I know this is the case for my WH20, but is it the same for my LW3? I
> was measuring voltages according to clays site and my schematics, there
> was a -110 going to the dmd but there is no +110(100?) going to the
> DMD? aybe if I write the listed voltages (schematics)and the actual
> voltages according to my multimeter....
>
> To the dmd glass=
> -110= -110.6
> -98= -101.2
> +5= 4.89
> +12= 11.87
> +68= 68.6
>
> To the dmd board=
> +5= 4.9
>
> Is there somewhere else I should be checking voltage?
>
> Thanks again...Tim
>
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

I have a couple of quick questions.....Does anyone know where I could
find one of these boards for sale? I remember seeing a couple a few
months back in the 35-65 dollar range and should have bought one then
"just in case"... Also, I know the different revisions of the board
reflected the different displays "128x16,128x32,etc...."What boards
would I be able to substitute for this one to get it to work in my LW3?
Also, does anyone have any ribbon for sale to replace mine, just in
case it is the ribbon? I checked mine visually and physically and they
appear fine, but maybe the ribbon needs to be replaced......Thanks
again for everyones help.....
 
G

Guest

Guest
Archived from groups: rec.games.pinball (More info?)

Ribbon cables can be purchased from Great Plains Electronics. Pretty
reasonable. Just Google for the web site.
 

Similar threads


ASK THE COMMUNITY