All my monitor problems at once :)

[enchntr]

Anyway, I have a WG 25K7131 monitor which I recapped and reconverged.  Everything looks good, except for the following:

• Bright white screen fades in and out going from white to dull white and back...
• vertical position doesn't allow me to move the image all the way to the top of the screen (I'm pegged on the V POS POT and the 50-60 POT doesn't help).  There's a good half there it needs to move (games like MK really show this because I can't center the image vertically)
• Two slight bars shown at the left hand side of the screen, something like this ||.  Could be burn in, but I don't think so...

Now, the white screen, is that blooming?  If so, I've already read the flyback may be the problem, so if it is blooming (can someone confirm), I'll replace that.  As for the Vertical position, I'm at a loss...

Thanks,
Ed

[Ken Layton]

I assume you bought a "k7000" capkit for this monitor.

The white fading could be bad or fluctuating "screen" voltage from the flyback. Replace the flyback.

Vertical problem could be capacitor C51 (which is NOT part of the cap kits). When this cap goes bad you either don't get enough vertical height or no vertical at all! The value of this cap is critical so if it drifts off value it affects vertical size.

Always double check this chassis for numerous bad solder joints.

[enchntr]

Well, off to Zanen I go then.

I did recap this with a K7000 kit a while ago and everything went smoothly.  I should have just done the flyback then since everything was out of the cabinet, but shouldn't be a problem taking it all apart again.

Thanks Ken!
Ed

[enchntr]

A followup for anyone reading.

Looks like both these issues are symptoms of REALLY BAD CONVERGENCE.   I attempted to do the convergence on my screen tonight, and while I think I did a pretty awesome job (then messing it up rightfully afterwards), it did solve my vertical issue and white level issue.

But now another issue which is driving me crazy.  Something tells me I may need to manually degauss this thing.  After going through the service manual on the convergence, I'm supposed to bring up a green belt, which should look like this:

 (  |   |   )

However, when I do this, I get this:

(  \  \  )

Which really messes me up when it comes to actually converging the thing...if I can't get straight lines here, lord knows I'm not getting straight lines on a cross hatch... 

Now, no amount of yoke adjustment or purity adjustment fixes this issue, and yes, a cap kit was installed a few months ago.

So, to all the experts out there...degauss, or take the chassis apart for a nice onceover?  I'm seriously considering replacing the tube soon as well because the burn in just sucks.   I'm actually more confident than ever on being able to do that, I just wish my troubleshooting skills were up to par.

Thanks,
Ed

[Ken Layton]

A picture that's slanted like that could be the yoke is twisted slightly or the horizontal holdadjustment not 100% spot on.

If your tube has lots of burnin then I would suggest getting a new tube.

[enchntr]

I think I figured out the problem....

It seems (I haven't checked yet, but been reading more) that there are what I thought were four pieces of paper between the yoke and tube at angles such as this at the top sides:

\\  //

I thought that they were shims to help the rubber wedges because the convergence was so off.

However, after reading this post, http://forum.arcadecontrols.com/index.php/topic,677.0.html I believe they are purity magnets, which could explain why it's so screwy.  Now to check.

As far as burn in goes, it's not that bad (only seen on bright white screens) that I need to run out and get a new tube.  But I'll be keeping an eye out just in case I decide it's time.

More to follow, and thanks again Ken.

Ed

[enchntr]

well crap, that wasn't it.  I'm done for the night as I seem to be making things worse.  Try again tomorrow. 

I don't understand what you're talking about Ken when you say the yoke may be twisted slightly...are you saying the yoke needs to be moved back to square, because it has been numerous times.  The screen is squared, but the colors are slanted...

                                                       |b\g\r\| instead of
                                                       |b|g|r|

No amount of yoke shifting ever squares this angle up...it seems to follow the yoke movement.

I'll wait for the flyback to arrive and check for broken or cold solder joints.  After that, I'm at a loss...

[enchntr]

Well, replaced the flyback today and although it didn't help with the angled green belt, I was able to get it straighter.

Anyway, I also resoldered C57 for the jailbars on the right hand side and that seemed to do the trick with that one.  I did some rudimentary convergence and it looks pretty good...not fantastic mind you, but pretty good.

The angled green belt is still bothering me though.  Maybe it's the direction I'm facing.