Weird monitor issue....Any help is appreciated.

Pengo13

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I have a cab that has a WG25k7193 chassis problem (monitor is vertically mounted). The chassis had a cap kit done by the previous owner, but I think it was not done correctly. I initially thought that the fixes would be simple, but I was wrong. There is some discoloration on the upper left, but that's just a little degaussing that it needs.

I went ahead and adjusted the Horizontal Hold knob, which fixed the distortion on the right almost completely (can barely be seen). My main problem now is getting the picture to cover the entire screen. No matter what knobs I move, the image will not move down. The Horizontal Position knob does nothing. The picture does jerk a bit as if it was trying to move down, but won't. I even moved that jumper wire on the board that is suppose to move the picture left, center, right with no luck. I tried adjusting the Horizontal Width coil, but that too won't move the picture. It does expand a bit but not move. I dont' know what's wrong. See attached pictures.

By the way, the monitor does have an excellent picture and comes on right away.

Please help. Thanks
 

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First check the electrolytic caps to be sure they are ALL good. If that checks out then try replacing the hor/vert processing IC.
 
Where can I order the hor/vert processing IC? The caps look new, but I don't know how to check them. What would prevent the Horiz Position knob from working?
 
i think its ic2..

i robbed mine from a donor chassis but im sure its available through bob or like mouser.com or digikey.com or ebay,etc


id go through that thing and make sure that the caps are the correct uf value at all locations. id also make sure you dont have any krappy solder connections...

After that id monkey with the 50/60 pot and see if you can cleanup that messed up edge.

Make sure you dont have a bad(worn) or cracked pot. Those crack very easily and sometimes you dont see it unless you really reallty look....
 
If you have the negative vertical sync hooked up, disconnect it....
 
The right side of the pictue was fixed by adjusting the Horiz Hold knob. The -vertical sync is not connected, only the -Horiz.

I just don't understand why the picture won't slide down. The picture looks excellent for it to be bad caps, but anything is possible. I guess that I was hoping that it was something simple that I missed. Has anyone seen this specific problem before?

Thanks for the help.
 
I have a cab that has a WG25k7193 chassis problem (monitor is vertically mounted). Please help. Thanks

I recall there being a 2n3904 right next to a pot that when it goes bad the adjustment does next to nothing to move the image. I dont recall if it was next to a vertical or horizontal position pot though... I do know that it was right next to the pot (if they are all on the board).

I'll see if I can find an image of the chassis on line and reply again.

Matt
 
OK, I found an image and marked teh transistor that I think causes this problem.

Matt
 

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Here's something to try. Turn on Dip Switch #1 on the board. That will flip the image. Then seee if you can adjust it by turning your position pot the other way.

And have you tried adjusting the 50/60Hz pot?
 
Thanks guys for the help. I have tried the 50-60Hz pot, but it only affects the left to right width. The monitor is vertically mounted so I might be confusing things a bit. I'm trying to get the top to bottom of the screen to fill. Flipping the image has no effect. Something is preventing the Horiz Position pot from working.

I'll check the chassis tonight again and take some pictures of it if anyone wants to see them.

Thanks
 
Thanks guys for the help. I have tried the 50-60Hz pot, but it only affects the left to right width. The monitor is vertically mounted so I might be confusing things a bit. I'm trying to get the top to bottom of the screen to fill. Flipping the image has no effect. Something is preventing the Horiz Position pot from working.

I'll check the chassis tonight again and take some pictures of it if anyone wants to see them.

Thanks

Repalce that transistor that I pointed out. At least I think thats a transistor in the pic. I'll look for a better image.

Matt
 
Nevermind that tranny... The problem was that the vertical posistion didnt work.

Matt
 
Dumb question, have you checked that the horizontal pot is actually good? Those ceramic pots break a lot if mis handled.

Matt
 
I'm going to revive this old thread just to point out that it has the same problem as a recent thread of mine regarding a G07. The only thing they have in common is that they are using the same board as a test...
 
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