Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: ireyes on May 04, 2006, 05:08:16 pm

Title: Monitor Control PCB (the thing with the pots)
Post by: ireyes on May 04, 2006, 05:08:16 pm

Hi, I believe I have a WG25k7191 monitor (at least from researching the markings on the tube itself).   Now the little pcb that has all the pots on it to control the different attributes seems to have broke.  The contrast pot is completely off and the Horizontal pos + horizontal hold controls do nothing at all when they are changed.   Here is a picture of the piece i am talking about:

 (http://filebox.vt.edu/users/ireyes/arcade/pcb.jpg)

Heres the link to full size:
http://filebox.vt.edu/users/ireyes/arcade/100_0055.jpg (http://filebox.vt.edu/users/ireyes/arcade/100_0055.jpg)

Now I can probably replace the pots but I need to know the value (resistance?) of the pots.  Does anybody know them or have experience with the same part?  Is there anyway to get a replacement part for this?

I can supply pictures of the monitor tube itself, if needed.

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: Ken Layton on May 04, 2006, 06:07:43 pm

That's called the remote adjustment board. The board you have pictured is definitely NOT from a Wells-Gardner 25K7191 or any of it's derivatives. A picture of the main monitor circuit board is needed.

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: ireyes on May 04, 2006, 07:32:52 pm

As you can tell, I dont really know much about monitor hardware.  Anyway I believe it is a zenith tube, and thought it was a wg chassis, doesnt look like it now.  Inside area is pretty dusty/dirty, but here are some links to pictures:

from the back:
(http://filebox.vt.edu/users/ireyes/arcade/100_0077.jpg)

pcb:
(http://filebox.vt.edu/users/ireyes/arcade/100_0080.jpg)
another:
(http://filebox.vt.edu/users/ireyes/arcade/100_0078.jpg)

more in at:
http://filebox.vt.edu/users/ireyes/arcade/ (http://filebox.vt.edu/users/ireyes/arcade/)


edit:  Just noticed that sharp image electronics logo at the bottom of one of the pics. 

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: Kevin Mullins on May 05, 2006, 02:38:27 pm

Looks like it might be Sharp Image SI 325 . . . . not much info found on it yet though.

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: Ken Layton on May 05, 2006, 05:53:28 pm

I would make a comment about this chassis, but I'm on a 28k dialup connection and your pictures are taking FOREVER to load. I don't have time for these huge file sizes to load. Got smaller versions?

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: ireyes on May 06, 2006, 10:43:40 am

changed the pictures in the post, in the process of resizing others.

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: Ken Layton on May 06, 2006, 11:07:42 am

Definitely a Sharp Image/Kortek monitor, but I don't know which model. I see a Sharp Image logo in the corner of the pc board. The monitor was original a Kortek that they branded for Sharp Image. 

Thank you for resizing the photos----that's much better. :applaud:

Title: Re: Monitor Control PCB (the thing with the pots)
Post by: Kevin Mullins on May 06, 2006, 03:38:01 pm

I found these values on several Sharp Image schematics.
Maybe worth checking against the ones you have.

H-Posi   = 10k
H-Hold   = 10k
V-Posi   = 1k
V-Size   = 100k
V-Hold   = 5k
Bright   = 2k
Contrast = 10k

Use your ohm meter to mesure the ones that aren't broken.
Measure the ohms between points A and B. The two legs side by side.
This should give you the total value of the pot.
Check between A and C or B and C  while turning it to see if it varies like it is supposed to.

   A ------
            >
            <------  C
            >
   B------

Hope this helps....... ???
(still not exactly sure which model you have though)