Monitor Still on LSD

[FrizzleFried]

Alright...I know that likely hope is all lost for this monitor,  but I wanted to take ONE LAST SHOT at it.  I posted about this montiors colors issue before but I didn't have it hooked up to a board that had full screen "solid color" screens. 

These are the best photos I can get of the problem and I even have a movie of what it does at the end.

ANY SUGGESTION as to how to fix this problem.  While it may look like some sort of magnetic degauss issue,  this monitor exhibits the same issue inside and outside of the cab with and without the onboard degauss coil connected and manual degaussing does not fix the problem.

I've been told it's a possible "SHADOW MASK" issue or an "OPEN ANODE" whatever that means.  The monitor shows images perfectly minus this color problem.

This is a 25" monitor and a pretty big hit if I can't get it to work correctly.

I know my chances are slim to none and slim is out smokin' something pungent,  but I figured I'd give it one last try before I give up on this tube.

The following screens are RED, GREEN, then BLUE...they are supposed to show solid color screens...





...and here is a short video clip (780k or so) of what the colors do...and it seems to be worse when it is cold...they actually somewhat stabilize when it warms up.

[Ken Layton]

You sure the yoke hasn't slid out of postion?

[FrizzleFried]

You sure the yoke hasn't slid out of postion?

The yoke is right up against the rubber spacers against the tube back.  I have NOT tried to remove it or put it back on.  Do you think that perhaps the yoke may be bad as opposed to the tube?  I mean I'd ASSUME (there I go again) a yoke may be easier to come by than a monitor tube?

[FrizzleFried]

Alright...so I in the back to take a real close look at this monitor and I discover the purity rings set is brittle as all hell and falling apart. 

Will that cause my symptoms?

Also,  can I use purity rings from another monitor type?  I have a QNIC 25" and a G07 19" I could pull the rings off of...are they the same regardless of size or are they different?  Can i mix manufactures  up?

[Kevin Mullins]

How odd..... I wouldn't think it was a purity ring or yoke issue. Because if those are suppose to be solid color test screens then the signal input for the other colors should be off. (correct?) I would think the other color guns would be completely turned off for those tests.
Seems like I've seen something similar to this somewhere and I'm just fishing to try and remember where.

Does it do the striped color thing with any other video inputs going to it?

What model monitor is it?

[Rickn]

Please tell me this is not a monitor from ALS Marketing or Budget Tube...

If it is you might as well throw it out.

Anyway, first off not the rings. The rings are actually there to correct minor imperfections in the tube and yoke combination due to manufacturing variances.

You can actualy get a reasonable picture without them. Your pictureis not "reasonable".

No unlikely the yoke has slipped that much, to get that the yoke would have to be back almost to the neck board.

If it was a Kortek 27" they had a problem with the yoke overheating - it actualy melted the epoxy on the yoke and the ferite bobbin came loose.

You can try loosening the yoke clamp and sliding the yoke back and forth on the neck, it may help.

Do not think it is a broken shadow mask as the position and order of the color bands indicate yoke position.

Download a copy of a G07 manual, in it there is a good write up how to set purity.


Good Luck

Rick Nieman
Rick@niemandisplays.com
www.niemandisplays.com

[grantspain]

casting my mind back to the 80's in relation to the shadow mask problem i am sure the pattern was random(like multi colour bursts) rather than the colour lines you have,its almost like a test bar pattern what you have
bloody strange fault mate
i can't remember anyone asking but what happens with the colour inputs disconnected and the screen volts up a bit to give a white raster

[FrizzleFried]

Yah...I moved the yoke up and down the neck and it wouldn't correct...


No worries though...because I fixed the problem.


The monitor was included in the Primal Rage cabinet that I traded (plus cash) for a Star Wars today.


Bye bye crazy ass monitor (it was a Wells Gardner K7100 BTW)...


I just wish I knew what was wrong with it.  HAD to be the yoke...right?

[bluevolume]

Man, I wish I had some kind of closure like that with my monitor.  I'd love to just be done with it and have something else to work with.