Makvision 2929 service menu

[lilshawn]

I have a badly setup Makvision 2929 monitor that needs some stuff adjusted in the service menu...

I was able to stumble upon the service adjustments menu and get the monitor adjusted properly, but was unable to save (don't know how) the changes, thus after powering up again, it's back the way it was.

How do i properly access the menu, save the changes, and does anybody know what the abbreviated adjustments are? Is there a PDF someplace that shows or explains this?

[lilshawn]

To enter the service mode you press and hold the menu button whilst you power on.



I'm not exactly sure what you have to do to save the settings (or even if you have to.)

I had some luck with pressing and holding the menu button for several seconds in an attempt to save the settings.

they seem to be holding.

FYI, The very last setting on the menu (labeled as "HU")... don't mess with it. changing it 2 values makes the monitor do BAD BAD things. (loses sync, the picture squashes down and appears to be on the verge of collapse.)

[fings1]

Thanks for that info lilshawn. I accidentally got into that menu once but couldn't figure out how to get back in.

Maybe someone has a a suggestion on how I can fix the issue I'm having. On my Makvision M2929D, both the right and left edges appear to be stretched. So much so that you can barely make out icons or text on the edges. The middle is fine. Here are a couple of pictures to show what I'm talking about:





I know I definitely have convergence problems with the red/blue/green guns aligning but is the stretching caused by this or could it be an adjustment or capacitor problem?

Thanks for any insights!

[lilshawn]

this issue is prevalent in all CRT monitors. the beam has to hit the phosphors at an angle so the color "bars" as you call them (called pixels) must be larger for the scanning electron beam to go through the aperture grill (or shadow mask depending on CRT manufacturer) and hit the phosphor dot.

basically because the beam has to exit the guns and turn a corner at like 110 degrees, the pixel must be slightly larger for it to hit it and effectively light it up.

this is also often why the focus is good in the middle but kinda bad in the corners. a "dual focus" style tube was an attempt to fix this issue.

[fings1]

Thanks lilshawn for educating me a bit!

Was hoping to be able to get it to look better but at least you saved me from doing a cap kit on it with no noticeable improvement as well as additional time spent on it.

All the best to you!

fings

[MonMotha]

Center convergence is controlled predominately by the convergence rings on the back of the yoke.  Edge convergence is controlled predominately by the tilt of the yoke on the neck of the tube.  If the yoke is not bonded, you could theoretically adjust this.  It's commonly seated using some little rubber wedges and RTV silicone.  You'll probably have to re-converge the center once you do it.  The yoke also has to be properly matched to the tube to get it perfect.

The yokes are generally attached and "calibrated" by hand at the factory.  Very high-end monitors will allow the technician quite a lot of time to get it all just right as it is a somewhat iterative process.  Cheaper monitors like your Makvision will have the tech on the clock the whole time and basically give him/her just barely enough time to get it done at all.  Lower end monitors are also prone to substituting tubes/yokes without fully verifying compatibility, and this can be the result.

This is not an easy task.  You'll probably just make it worse if you mess with it.  Yours may already be as good as it's going to get due to aforementioned reasons.  I'm not suggesting that you do it, just letting you know it may be an option.

[fings1]

Thanks MonMotha...and just as I was about to walk away from it, I get pulled back in...hahaha

I definitely get the "you'll probably make it worse" comment. I'll have to think long and hard about it first.

Thanks again for sharing.