Someone just gave me a 19" CRT monitor, and I noticed a geometry
problem with it. It seems that the top edge and bottom edge of the
image are not parallel with the top and bottom of the monitor. The
right side of the top edge and bottom edge of the image touch the top
and bottom of the screen, but the left side of the top edge and bottom
edge are a few millimeters from touching the top and bottom of the
screen.
This is something that a t****zoid adjustment would fix, and the
monitor does have a t****zoid adjustment. But it only adjusts the
sides of the image, not the top and bottom. There is nothing I can do
about this problem (without opening up the monitor), right?
<void.no.spam.com@gmail.com> wrote in message
news:a5be52d6-87ee-4f90-a0dc-8f06257e53a9@8g2000hse.googlegroups.com...
> Someone just gave me a 19" CRT monitor, and I noticed a geometry
> problem with it. It seems that the top edge and bottom edge of the
> image are not parallel with the top and bottom of the monitor. The
> right side of the top edge and bottom edge of the image touch the top
> and bottom of the screen, but the left side of the top edge and bottom
> edge are a few millimeters from touching the top and bottom of the
> screen.
>
> This is something that a t****zoid adjustment would fix, and the
> monitor does have a t****zoid adjustment. But it only adjusts the
> sides of the image, not the top and bottom. There is nothing I can do
> about this problem (without opening up the monitor), right?
How long did you give it to warm up? Make sure its warmed properly (might be
an hour or so) before adjusting things.
"GT" <ContactGT_remove_@hotmail.com> wrote in message
news:010264d9$0$17403$c3e8da3@news.astraweb.com...
>> This is something that a t****zoid adjustment would fix, and the
>> monitor does have a t****zoid adjustment. But it only adjusts the
>> sides of the image, not the top and bottom. There is nothing I can do
>> about this problem (without opening up the monitor), right?
>
> How long did you give it to warm up? Make sure its warmed properly (might
> be an hour or so) before adjusting things.
But even after that - no, it's very likely that there is nothing you can
do to completely adjust out this error. You might get lucky and find
an additional adjustment inside, but that's more and more unlikely
these days. If you don't see it on the front panel or in the OSD, it's
probably not there at all.
"philo" wrote in message
news:qMedndCvm-4paX7anZ2dnUVZ_rCtnZ2d@athenet.net...
>
> Yes, there generally are quite a few adjustments inside the monitor
> but unless one is familiar with working on CRT's I'd not do it.
> There is HIGH VOLTAGE in there!
And the adjustments on the yoke assembly are independent. Once you
find you went the wrong way with a few settings, you might not be able
to back out to what you had before unless you record exactly how many
turns or partial turns you made, in what order, and if you moved the
yoke itself. If you go inside, figure on if you fix it then fine, if
you don't then you already planned on discarding it.
You might also try changing the refresh frequency in Windows. You
might observe different effects in alignment that then you can adjust
out.
"Bob Myers" <nospamplease@address.invalid> wrote in message
news:fs0r7j$5q7$1@usenet01.boi.hp.com...
>
> "GT" <ContactGT_remove_@hotmail.com> wrote in message
> news:010264d9$0$17403$c3e8da3@news.astraweb.com...
>>> This is something that a t****zoid adjustment would fix, and the
>>> monitor does have a t****zoid adjustment. But it only adjusts the
>>> sides of the image, not the top and bottom. There is nothing I can do
>>> about this problem (without opening up the monitor), right?
>>
>> How long did you give it to warm up? Make sure its warmed properly (might
>> be an hour or so) before adjusting things.
>
> But even after that - no, it's very likely that there is nothing you can
> do to completely adjust out this error. You might get lucky and find
> an additional adjustment inside, but that's more and more unlikely
> these days. If you don't see it on the front panel or in the OSD, it's
> probably not there at all.
>
> Bob M.
>
Yes, there generally are quite a few adjustments inside the monitor
but unless one is familiar with working on CRT's I'd not do it.
There is HIGH VOLTAGE in there!
<void.no.spam.com@gmail.com> wrote in message
news:a5be52d6-87ee-4f90-a0dc-8f06257e53a9@8g2000hse.googlegroups.com...
> Someone just gave me a 19" CRT monitor, and I noticed a geometry
> problem with it. It seems that the top edge and bottom edge of the
> image are not parallel with the top and bottom of the monitor. The
> right side of the top edge and bottom edge of the image touch the top
> and bottom of the screen, but the left side of the top edge and bottom
> edge are a few millimeters from touching the top and bottom of the
> screen.
CRT monitors are designed to have about a 1/4 inch of blank display all the
way around the picture. Set it this way and you probably won't notice the
misalignment.
> Someone just gave me a 19" CRT monitor, and I noticed a geometry
> problem with it. It seems that the top edge and bottom edge of the
> image are not parallel with the top and bottom of the monitor. The
> right side of the top edge and bottom edge of the image touch the top
> and bottom of the screen, but the left side of the top edge and bottom
> edge are a few millimeters from touching the top and bottom of the
> screen.
>
> This is something that a t****zoid adjustment would fix, and the
> monitor does have a t****zoid adjustment. But it only adjusts the
> sides of the image, not the top and bottom.
You may want to ask in sci.electronics.repair because there are a lot
of TV/monitor technicians there. I think I've read there that a
problem like this is in the horizontal deflection circuitry, possibly
the damper diode, which may be a separate device or built into the
horizontal output transistor.
> however I have since removed the yoke
Good luck reinstalling it exactly as it was and getting the color
convergence restored.
><void.no.spam.com@gmail.com> wrote in message
>news:a5be52d6-87ee-4f90-a0dc-8f06257e53a9@8g2000hse.googlegroups.com...
>> Someone just gave me a 19" CRT monitor, and I noticed a geometry
>> problem with it. It seems that the top edge and bottom edge of the
>> image are not parallel with the top and bottom of the monitor. The
>> right side of the top edge and bottom edge of the image touch the top
>> and bottom of the screen, but the left side of the top edge and bottom
>> edge are a few millimeters from touching the top and bottom of the
>> screen.
>
>CRT monitors are designed to have about a 1/4 inch of blank display all the
>way around the picture.
Since when? Ideally, the image shoud cover 100% of the usable area.
(Of course, the tube itself is larger than that.)
>Set it this way and you probably won't notice the misalignment.
"chrisv" <chrisv@nospam.invalid> wrote in message
news:rebiu3pcseavscittnkse33pnqs30trac4@4ax.com...
>>CRT monitors are designed to have about a 1/4 inch of blank display all
>>the
>>way around the picture.
>
> Since when? Ideally, the image shoud cover 100% of the usable area.
> (Of course, the tube itself is larger than that.)
That all depends on what you define as the "usable area," and
whether or not the opening in the monitor bezel encroaches on
that area.
In most CRT specs (the tube itself, not the monitor), there is a
"recommended image area" which is smaller than the full extent
of the phosphor screen. In part, this area is determined by what's
going on re the curvature of the inside of the glass faceplate as you
get to the edges of the tube (obviously, at some point that inner
surface is no longer anything even remotely resembling "flat," and
the geometry, etc., starts to go bad quicky in those regions. In
part, the area is also determined by the performance of the yoke
(at least a "typical" yoke as expected for that tube type, the focus
electronics, etc., convergence, etc., also going away as you get
close to the extreme edges. For monitor tubes, this results in
the optimum image area being somewhat smaller than what you
might expect from just looking at how big an area the phosphor
covers.
TVs are a bit different in that they are commonly "overscanned" -
i.e.., the scanned image actually extents beyond the edges of the
phosphor screen by about 5-10%. This basically hides edge
geometry and other problem by placing them where the viewer
can't possibly see them.
On Tue, 25 Mar 2008 11:54:32 -0500, chrisv
<chrisv@nospam.invalid> wrote:
>Calab wrote:
>
>><void.no.spam.com@gmail.com> wrote in message
>>news:a5be52d6-87ee-4f90-a0dc-8f06257e53a9@8g2000hse.googlegroups.com...
>>> Someone just gave me a 19" CRT monitor, and I noticed a geometry
>>> problem with it. It seems that the top edge and bottom edge of the
>>> image are not parallel with the top and bottom of the monitor. The
>>> right side of the top edge and bottom edge of the image touch the top
>>> and bottom of the screen, but the left side of the top edge and bottom
>>> edge are a few millimeters from touching the top and bottom of the
>>> screen.
>>
>>CRT monitors are designed to have about a 1/4 inch of blank display all the
>>way around the picture.
>
>Since when? Ideally, the image shoud cover 100% of the usable area.
>(Of course, the tube itself is larger than that.)
>
>>Set it this way and you probably won't notice the misalignment.
>
>Not sure why not...
It depends on the cause, on a typical CRT the last few
percent of the usable area is geometrically distorted. Some
would rather have the entire display bigger by using this
area (including a monitor manufacturer selling by # of
inches who doesn't want to irk the customer by not using as
much of the space as possible) but some would rather leave a
small border to keep geometry correct.
Maybe a better question is why fool around with an old CRT
monitor with problems - probably why it was given away.
There might be an adjustment inside but without a service
manual all one can do is open it and see what they see, or
pay a tech to look at it but I hardly think it worthwhile
for an old 19" CRT.
CRT monitor geometry problem 
Linear Mode
