CRT Monitor Out of Focus

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Kadin2048 - 27 Aug 2008 02:03 GMT

I have an old (circa 2001) 19" Mag Innovision CRT monitor that has served
me well throughout the years, up until very recently.

Ever since a recent move, it's like the picture is very /slightly/ out
of focus. Almost like everything on the screen has an anti-alias
filter applied to it, or maybe a 1.5px blur. Nothing in the system
configuration has been changed (and elements that normally shouldn't
be anti-aliased are blurry; it's not just a text smoothing issue).

Also, it seems as though the center of the monitor is slightly worse
than at the edges. I actually noticed the blur because it seemed like
web pages and email were easier to read when the text was near the
edge of the screen, not in the center. Also, it was giving me a
wretched headache.

I've never seen anything like this happen before. Is it physically
possible for a CRT monitor to get 'knocked' out of focus? (And if so,
is it something that can be adjusted or fixed?) It's not like the
monitor was abused particularly badly -- I just carried it to the car,
drove it around for a few miles, then carried it down and set it on
the desk in the new place.

There's no sharpness or focus control in the monitor's settings, and
I'm using the same DVI-to-VGA adapter that I was using in the old
location (to connect to my G5's stock NVidia card), so that doesn't
seem like it would be an issue.

Anyone have any thoughts? I suppose the monitor doesn't really owe me
anything at this point, but I'd hate to replace it before knowing
whether it's salvageable or not.

Thanks,
Kadin

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isw - 27 Aug 2008 05:31 GMT

> I have an old (circa 2001) 19" Mag Innovision CRT monitor that has served
> me well throughout the years, up until very recently.
[quoted text clipped - 13 lines]
> I've never seen anything like this happen before. Is it physically
> possible for a CRT monitor to get 'knocked' out of focus?

Yes.

> (And if so,
> is it something that can be adjusted or fixed?)

Usually.

> It's not like the
> monitor was abused particularly badly -- I just carried it to the car,
[quoted text clipped - 9 lines]
> anything at this point, but I'd hate to replace it before knowing
> whether it's salvageable or not.

If you feel comfortable fiddling around inside a monitor (responsibility
disclaimer here), you can try this:

Open it up, including the metal shielding. Find the "ultor" electrode
connector on the conical part of the CRT (heavy wire going into a
"suction cup" looking affair -- it'll have fine black dust all over it).
Trace it back to the plastic object at the other end of the wire. That's
the high-voltage transformer.

On the side of the HV transformer (probably the one facing towards the
edge of the board) will be one (or possibly two) plastic shafts with
screwdriver slots in the top. There will probably be something that
looks like paint "gluing" them in place. Those are the focus
adjustment(s). Now that you know where they are, you can probably put
the metal shielding back together and get to the adjustments through
holes in it (make them if you feel like it and they don't exist).

Fire up the monitor and arrange for it to show an image where sharpness
would be evident. Let it run until it's good and warm -- thirty minutes,
say (very slight changes inside the CRT due to thermal expansion can
change the focus). *Slightly* twist the focus control for best overall
sharpness (if there are two, the one labeled "1" is for the center of
the screen and "2" is for the corners; work them alternately for best
results). Don't worry about the paint on the shafts; the first twist
will crack it loose, and you don't have to replace it with anything.

Sometimes, focus changes just due to the effect of age on the focus
adjusters themselves.

Isaac

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Kadin2048 - 27 Aug 2008 17:44 GMT

> Open it up, including the metal shielding. Find the "ultor" electrode
> connector on the conical part of the CRT (heavy wire going into a
[quoted text clipped - 6 lines]
>
> Isaac

Thanks -- that's exactly the information I was hoping for.

I think I'll do some more research and price replacements and then
decide whether it's worth the time to open up and try to fix. (Been a
while since I've done any HV work; I'll have to dig up my discharge
probe from wherever it is...)

Thanks!
Kadin.

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Ecnerwal - 30 Aug 2008 02:52 GMT

> Anyone have any thoughts? I suppose the monitor doesn't really owe me
> anything at this point, but I'd hate to replace it before knowing
> whether it's salvageable or not.

Practically speaking, recycle it and get a 22" flat screen. Your power
bill will thank you, and you'll have a lot more pixels. 22 seems to be
the present sweet spot on the bang/buck curve.

If you are really in love with having a CRT, look in the free and
computer sections on your local craigslist, they show up free or cheap
all the time - you can probably get a 21" CRT with some patience.

If you are going to muck with the adjusters, you need alignment tools -
non-conductive, non-magnetic high-voltage screwdrivers. Probably cost
you more than that used-in-focus craigslist monitor will.

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Don Bruder - 30 Aug 2008 04:55 GMT

> > Anyone have any thoughts? I suppose the monitor doesn't really owe me
> > anything at this point, but I'd hate to replace it before knowing
[quoted text clipped - 11 lines]
> non-conductive, non-magnetic high-voltage screwdrivers. Probably cost
> you more than that used-in-focus craigslist monitor will.

Only if the monitor costs less than about 5 bucks.

(Unless you're going with the super-deluxe version, I have yet to see a
more-than-adequate for home/hobby use alignment set cost more than a
couple bucks and tax.)

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isw - 30 Aug 2008 05:42 GMT

> > Anyone have any thoughts? I suppose the monitor doesn't really owe me
> > anything at this point, but I'd hate to replace it before knowing
[quoted text clipped - 3 lines]
> bill will thank you, and you'll have a lot more pixels. 22 seems to be
> the present sweet spot on the bang/buck curve.

I'm not convinced that flat is the way to go if you're interested in
color accuracy (photo editing, say). At least, flat panels which are
good at that are not on the cheap end of the curve.

> If you are really in love with having a CRT, look in the free and
> computer sections on your local craigslist, they show up free or cheap
[quoted text clipped - 3 lines]
> non-conductive, non-magnetic high-voltage screwdrivers. Probably cost
> you more than that used-in-focus craigslist monitor will.

Well, I've tweaked a lot of focus adjustments, and I've never used
anything but plain old screwdrivers. There's not really any high voltage
down on the side of the HVT where the adjustments are. Non-magnetic
(really, just not magnetized) also isn't necessary. And even magnetized
tools won't cause a problem as long as you keep them away from the CRT
and the steel chassis.

If you want to be super-cautious, take a piece of bare wire a couple of
feet long, wrap one end around the screwdriver shaft a few times, and
fasten the other end under a screw head someplace on the chassis or
shielding. I don't do any of that; I just stick a screwdriver through a
hole in the shielding.

Isaac

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Michael - 08 Sep 2008 16:33 GMT

> I have an old (circa 2001) 19" Mag Innovision CRT monitor that has served
> me well throughout the years, up until very recently.
[quoted text clipped - 4 lines]
> configuration has been changed (and elements that normally shouldn't
> be anti-aliased are blurry; it's not just a text smoothing issue).

Probably needs degaussing. Some monitors have a built-in feature that
does this. Maybe by push-button or menu selection.
Good luck.

- Mike

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isw - 08 Sep 2008 18:19 GMT

In article
<crotchety1-DE978A.08331308092008@newsclstr02.news.prodigy.com>,

> > I have an old (circa 2001) 19" Mag Innovision CRT monitor that has served
> > me well throughout the years, up until very recently.
[quoted text clipped - 7 lines]
> Probably needs degaussing. Some monitors have a built-in feature that
> does this. Maybe by push-button or menu selection.

As a broad statement, poor focus is caused by something being out of
adjustment back in the "neck" of the CRT, while color misregistration is
caused by something being magnetized up near the screen. Degaussing will
only fix the latter.

It is *possible* for something near the back of the CRT to become
magnetized, but it is not at all likely, and the degaussing function
built in to the monitor wouldn't be able to fix it anyway.

Isaac

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Mac Forum / General / Hardware / September 2008

CRT Monitor Out of Focus