Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Are there any other convergence controls I could adjust to get it
closer, like pots on one of the boards? Or how about trying to tweak the
deflection coils a tiny bit?

This monitor is on its last legs, so I'm not going to be investing a lot
(in terms of time, and $0 in money) in it. I'd just like to know if I
can get a few more weeks or months of use out of it.

Pity, really: when it worked well, this was an outstanding monitor.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

On Sat, 27 Feb 2010 20:25:26 -0800
David Nebenzahl wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.


Try demagnetizing it first, especially if your monitor has a built-in
degaussing button. The next step is to degauss with an external
demagnitizer. There are TV degaussing coils for this (check Ebay), but
you might be able to make do with something like a bulk tape eraser
if you already have one.

Color convergence problems will show up as red, blue or green outlines
and/or duplicate images - like when the colors don't align on newspaper
comic sections. If the ghosts you see are not in different colors,
then it is not a convergence problem. The focus control is often very
easy to unintentionally turn although a misadjusted focus control
generally causes blurriness rather than ghosts.


Cheers,

Mike Shell

On 2/27/2010 9:48 PM Michael Shell spake thus:

On Sat, 27 Feb 2010 20:25:26 -0800
David Nebenzahl wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Try demagnetizing it first, especially if your monitor has a built-in
degaussing button. The next step is to degauss with an external
demagnitizer. There are TV degaussing coils for this (check Ebay), but
you might be able to make do with something like a bulk tape eraser
if you already have one.

No bulk eraser, but I do have a couple of tape head demagnetizers;
wonder if they'd do any good. But the monitor has a built-in degausser
anyhow.

Color convergence problems will show up as red, blue or green outlines
and/or duplicate images - like when the colors don't align on newspaper
comic sections. If the ghosts you see are not in different colors,
then it is not a convergence problem. The focus control is often very
easy to unintentionally turn although a misadjusted focus control
generally causes blurriness rather than ghosts.

It's definitely a convergence problem. I can see the colors shifting
when I adjust the on-screen convergence control, but not far enough to
eliminate the ghosts (which are definitely in different colors). The
focus is fine.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

There's an on-screen convergence control, but even with it
cranked all the way over (to 100/100 for the horizontal control,
76 for the vertical), there are still highly visible "ghosts" on screen.

My ViewSonic with a Diamondtron CRT also has two on-screen convergence
controls. However, I suspect they're for tweaking. There are almost
certianly other convergence controls within the monitor. You probably kocked
one loose (so to speak) during cleaing.

"David Nebenzahl" wrote in message
.com...
On 2/27/2010 9:48 PM Michael Shell spake thus:

On Sat, 27 Feb 2010 20:25:26 -0800
David Nebenzahl wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Try demagnetizing it first, especially if your monitor has a built-in
degaussing button. The next step is to degauss with an external
demagnitizer. There are TV degaussing coils for this (check Ebay), but
you might be able to make do with something like a bulk tape eraser
if you already have one.

No bulk eraser, but I do have a couple of tape head demagnetizers; wonder
if they'd do any good. But the monitor has a built-in degausser anyhow.

Color convergence problems will show up as red, blue or green outlines
and/or duplicate images - like when the colors don't align on newspaper
comic sections. If the ghosts you see are not in different colors,
then it is not a convergence problem. The focus control is often very
easy to unintentionally turn although a misadjusted focus control
generally causes blurriness rather than ghosts.

It's definitely a convergence problem. I can see the colors shifting when
I adjust the on-screen convergence control, but not far enough to
eliminate the ghosts (which are definitely in different colors). The focus
is fine.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"


If it does relate to degaussing, the built-in coil, while not strong enough
to fix it on one or two tries, might get the job done over the course of
time, which is to say, a certain number of degauss cycles. Sony CRT's can be
damaged by conventional hand held coils, though in practice I've not seen
this happen. I think that particular caution only applied to their larger
CRT's.

Mark Z.

Michael Shell wrote in
news:20100228004851.0c71229b@bashir:

On Sat, 27 Feb 2010 20:25:26 -0800
David Nebenzahl wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.


Try demagnetizing it first, especially if your monitor has a built-in
degaussing button. The next step is to degauss with an external
demagnitizer. There are TV degaussing coils for this (check Ebay), but
you might be able to make do with something like a bulk tape eraser
if you already have one.

Color convergence problems will show up as red, blue or green outlines
and/or duplicate images - like when the colors don't align on newspaper
comic sections. If the ghosts you see are not in different colors,
then it is not a convergence problem. The focus control is often very
easy to unintentionally turn although a misadjusted focus control
generally causes blurriness rather than ghosts.


Cheers,

Mike Shell




first,there's a difference between "convergence" and "purity".

when setting up a CRT,you first adjust purity,by displaying a red screen
and adjusting yoke magnets for even color and no green or blue areas.
But before that,you degauss with an EXTERNAL coil,as the internal coils are
not powerful enough.

Convergence is adjusted by displaying a crosshatch or dot grid and
adjusting the appropriate controls to merge the R-G-B lines or dots to make
white lines or dots.
On some sets,you may also have to use adhesive magnet strips to achieve
decent convergence in the corners.I used to do this at Tektronix on their
650 and 670 series monitors.

--
Jim Yanik
jyanik
at
localnet
dot com

Mark Zacharias Inscribed thus:

"David Nebenzahl" wrote in message
.com...
On 2/27/2010 9:48 PM Michael Shell spake thus:

On Sat, 27 Feb 2010 20:25:26 -0800
David Nebenzahl wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron
tube. In so doing I seem to have knocked the convergence out of
whack, even though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked
all the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Try demagnetizing it first, especially if your monitor has a
built-in degaussing button. The next step is to degauss with an
external demagnitizer. There are TV degaussing coils for this (check
Ebay), but you might be able to make do with something like a bulk
tape eraser if you already have one.

No bulk eraser, but I do have a couple of tape head demagnetizers;
wonder if they'd do any good. But the monitor has a built-in
degausser anyhow.

Color convergence problems will show up as red, blue or green
outlines and/or duplicate images - like when the colors don't align
on newspaper comic sections. If the ghosts you see are not in
different colors, then it is not a convergence problem. The focus
control is often very easy to unintentionally turn although a
misadjusted focus control generally causes blurriness rather than
ghosts.

It's definitely a convergence problem. I can see the colors shifting
when I adjust the on-screen convergence control, but not far enough
to eliminate the ghosts (which are definitely in different colors).
The focus is fine.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"


If it does relate to degaussing, the built-in coil, while not strong
enough to fix it on one or two tries, might get the job done over the
course of time, which is to say, a certain number of degauss cycles.
Sony CRT's can be damaged by conventional hand held coils, though in
practice I've not seen this happen. I think that particular caution
only applied to their larger CRT's.

Mark Z.

Simply rotating the screen 15 - 20 degrees is enough to cause colour
patches to come and go in the corners on my Trinitron tubed iiyama.
The Trinitron tubes seem to be very sensitive to any magnetic
disturbance.

--
Best Regards:
Baron.

On Feb 27, 10:32*pm, David Nebenzahl wrote:
On 2/27/2010 9:48 PM Michael Shell spake thus:





On Sat, 27 Feb 2010 20:25:26 -0800
David Nebenzahl wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Try demagnetizing it first, especially if your monitor has a built-in
degaussing button. The next step is to degauss with an external
demagnitizer. There are TV degaussing coils for this (check Ebay), but
you might be able to make do with something like a bulk tape eraser
if you already have one.

No bulk eraser, but I do have a couple of tape head demagnetizers;
wonder if they'd do any good. But the monitor has a built-in degausser
anyhow.

Color convergence problems will show up as red, blue or green outlines
and/or duplicate images - like when the colors don't align on newspaper
comic sections. If the ghosts you see are not in different colors,
then it is not a convergence problem. The focus control is often very
easy to unintentionally turn although a misadjusted focus control
generally causes blurriness rather than ghosts.

It's definitely a convergence problem. I can see the colors shifting
when I adjust the on-screen convergence control, but not far enough to
eliminate the ghosts (which are definitely in different colors). The
focus is fine.

--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

In a pinch, you can use a cheap AC powered pencil sharpener. I once
had to do this and the convergence was actually better than it had
ever been before.

Except, be careful, or you can permanently warp the nickel shield/
mask. Approach degaussing cautiously

On Feb 28, 8:41*am, Meat Plow wrote:
On Sat, 27 Feb 2010 20:25:26 -0800, David Nebenzahl
wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Are there any other convergence controls

If it has static adjustments on the neck of the crt you may have
disturbed those.

I second that.

So, center the 'onscreen' convergence controls, degauss, then power up
with the back of the monitor off, display a white-grid-on-black-
background
pattern, and adjust the ring magnets (usually nearer the electron gun,
in
the form of a pair of rings with tabs). Tabs apart gives higher
field,
rotating both rings together changes the direction. It's tedious,
but
rewarding.

There also may be small magnets glued around the yoke (closer to the
screen) that do fine corrections.

On Sat, 27 Feb 2010 20:25:26 -0800, David Nebenzahl
wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Are there any other convergence controls I could adjust to get it
closer, like pots on one of the boards? Or how about trying to tweak the
deflection coils a tiny bit?

This monitor is on its last legs, so I'm not going to be investing a lot
(in terms of time, and $0 in money) in it. I'd just like to know if I
can get a few more weeks or months of use out of it.

Pity, really: when it worked well, this was an outstanding monitor.


See if it has an hstat control. If it does adjust it for good
convergence. Chuck

If you physically moved any of the ring magnets, you will have to make
sure they are put back exactly how they were before moving them. You
can make all the control adjustments you want, and the convergence
cannot go back unless the magnets are properly re-set.

There is a proper procedure to do convergence alignment that requires
proper training to get this right. This is too involved to describe in
the scope of an email. These magnets affect both the convergence and
purity alignment.


Jerry G

______________________________


On Feb 27, 11:25*pm, David Nebenzahl wrote:
Well, I tried cleaning the dust out of my Dell-branded Trinitron tube.
In so doing I seem to have knocked the convergence out of whack, even
though I was really careful vacuuming around the CRT.

There's an on-screen convergence control, but even with it cranked all
the way over (to 100/100 for the horizontal control, 76 for the
vertical), there are still highly visible "ghosts" on screen.

Are there any other convergence controls I could adjust to get it
closer, like pots on one of the boards? Or how about trying to tweak the
deflection coils a tiny bit?

This monitor is on its last legs, so I'm not going to be investing a lot
(in terms of time, and $0 in money) in it. I'd just like to know if I
can get a few more weeks or months of use out of it.

Pity, really: when it worked well, this was an outstanding monitor.

--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

On 2/28/2010 11:36 AM whit3rd spake thus:

On Feb 28, 8:41 am, Meat Plow wrote:

On Sat, 27 Feb 2010 20:25:26 -0800, David Nebenzahl
wrote:

Well, I tried cleaning the dust out of my Dell-branded Trinitron
tube.

There's an on-screen convergence control, but even with it
cranked all the way over (to 100/100 for the horizontal control,
76 for the vertical), there are still highly visible "ghosts" on
screen.

If it has static adjustments on the neck of the crt you may have
disturbed those.

I second that.

So, center the 'onscreen' convergence controls, degauss, then power
up with the back of the monitor off, display a white-grid-on-black-
background pattern, and adjust the ring magnets (usually nearer the
electron gun, in the form of a pair of rings with tabs). Tabs apart
gives higher field, rotating both rings together changes the
direction. It's tedious, but rewarding.

There also may be small magnets glued around the yoke (closer to the
screen) that do fine corrections.

So I'm curious about this adjustment procedure. Are you saying you can
do this--safely--with the tube powered up? How are the ring magnets
secured--screw clamps or some such?

I assume these are around the neck of the CRT, right? As long as they're
far, far away from any HV, I'm considering trying this. Nothing to lose
except this monitor which is dying anyway. So do you loosen the magnet,
move it, then retighten?

More details, pleeze.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

So I'm curious about this adjustment procedure. Are you saying
you can do this--safely--with the tube powered up? How are the
ring magnets secured--screw clamps or some such?

Techs have been doing this for 56 years with the tube "powered up". How
would you do it otherwise?

On 3/16/2010 3:33 AM William Sommerwerck spake thus:

[I wrote:]

So I'm curious about this adjustment procedure. Are you saying
you can do this--safely--with the tube powered up? How are the
ring magnets secured--screw clamps or some such?

Techs have been doing this for 56 years with the tube "powered up". How
would you do it otherwise?

Wellll, I'm not a "tech" (and I see no shame in admitting it), so that's
why I'm asking.

Thanks for the confirmation, though.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"