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From: Jerry G. on 2 Mar 2010 22:28
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 <nob...(a)but.us.chickens> 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"

From: David Nebenzahl on 16 Mar 2010 02:24
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
>> <nob...(a)but.us.chickens>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"
From: William Sommerwerck on 16 Mar 2010 07:33
> 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?


From: David Nebenzahl on 20 Mar 2010 15:32
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"
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