How fix lines on CRT from signal lead ?

[lsmartino]

CBFalconer ha escrito:

Wiggling the flyback can disturb the horizontal sync, which in turn
disturbs the HV, which in turn affects the picture size.

Please, reread the post. I said "...A bad flyback will not worsen or
improve by "wiggling" the VGA CABLE OF THE MONITOR..." Did you noticed
the "VGA CABLE" part of the sentence?

And the Flyback isn´t even in the same PCB as the VGA cable is. So
there is no way that disturbing the VGA cable will cause any physical
displacement of the flyback.

 

[Rod Speed]

Wiggling the cable wiggles the entire monitor.

Wrong again, particularly when you deliberately
restrain the cable and wiggle/flex the video card end.

 

[johns]

That pulls the wire .. which pulls the other end connector
.... which pulls the crt card .. which wiggles the crt ..
which wiggles the main board ... you can't test that
way. It will fool you a million times.

johns

 

[Rod Speed]

Rod Speed wrote

That pulls the wire ..

No it doesnt if you restrain the cable.

which pulls the other end connector

No it doesnt if you restrain the cable.

... which pulls the crt card ..

No it doesnt if you restrain the cable.

which wiggles the crt ..

No it doesnt if you restrain the cable.

which wiggles the main board ...

No it doesnt if you restrain the cable.

you can't test that way.

Corse you can.

It will fool you a million times.

Only those that are very easily fooled and cant
even manage to restrain the cable while flexing
the video card end.

 

[Michael Kennedy]

Only those that are very easily fooled and cant
even manage to restrain the cable while flexing
the video card end.

Agreed... Sounds like a bad VGA cable or possibly the connector on the
video card. I don't even know why there is even any debate about this.
Replace the VGA cable first. If the problem still exsists afterwards it is
elsewhere. The guy talking about the flyback is just trying to be a troll
and start a huge arguement over nothing.

 

[mike.j.harvey]

Nothing to notice except you jumping at bogeymen.

The following extracted from:-

http://en.wikipedia.org/wiki/Internet_troll#Attention-seeking_trolls

Attention-seeking trolls

This class of trolls seeks to incite as many responses as possible and
to absorb a disproportionate share of the collective attention span.

* Messages containing a deliberate flaw or error: "I think 2001: A
Space Odyssey is Roman Polanski's best film." Or "Federico Fellini is
the Greatest Living American Director"

*Asking for help with an implausible task or problem: "How do I season
my Crock Pot? I don't want everything I cook in it to taste the same."

*Intentionally naive questions: "Can I cook pasta in Evian instead of
water?"

*Intentionally posting an outrageous argument, deliberately constructed
around a fundamental but obfuscated flaw or error. Often the poster
will become defensive when the argument is refuted, and may continue
the thread through the use of further flawed arguments; this is
referred to as "feeding" the troll.

 

[meow2222]

Never ever could bullshit its way out of a wet paper bag.
Pity the FBT isnt even on that board.

If you dont think wiggling a thick fat video cable can wiggle the
plastic base that the main board sits on, and thus the main board, then
either you havent repaired too many monitors, or youre a moron. Almost
certainly both.

NT

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed wrote

If you dont think wiggling a thick fat video cable can wiggle the
plastic base that the main board sits on, and thus the main board,

Never ever could bullshit its way out of a wet paper bag.

then either you havent repaired too many monitors,
or youre a moron. Almost certainly both.

Any 2 year old could leave that for dead.

Get one to help you before posting again, if anyone is
actually stupid enough to let you anywhere near one.

 

[Rod Speed]

(e-mail address removed) wrote

Rod Speed wrote

The following extracted from:-

http://en.wikipedia.org/wiki/Internet_troll#Attention-seeking_trolls

Attention-seeking trolls

This class of trolls seeks to incite as many responses as possible and
to absorb a disproportionate share of the collective attention span.

* Messages containing a deliberate flaw or error: "I think 2001: A
Space Odyssey is Roman Polanski's best film." Or "Federico Fellini is
the Greatest Living American Director"

*Asking for help with an implausible task or problem: "How do I season
my Crock Pot? I don't want everything I cook in it to taste the same."

*Intentionally naive questions: "Can I cook pasta in Evian instead of
water?"

*Intentionally posting an outrageous argument, deliberately
constructed around a fundamental but obfuscated flaw or error. Often
the poster will become defensive when the argument is refuted, and
may continue the thread through the use of further flawed arguments;
this is referred to as "feeding" the troll.

All completely irrelevant to whether what he was doing
had anything what so ever to do with attention seeking.

He may well be just another rather irrational individual.

 

[kony]

If you dont think wiggling a thick fat video cable can wiggle the
plastic base that the main board sits on, and thus the main board, then
either you havent repaired too many monitors, or youre a moron. Almost
certainly both.

NT

It depends entirely on how well that cable is fixed
internally. Some certainly would but quite a few wouldn't.
So yes it's possible but not necessary true.

 

[Eric]

Hi Jon

As electronic equipment gets older, the Electrolytics begin to fail, the ESR
begins to rise.
A failing Electrolytic would cause top fold over.
If you look at a typical vertical drive circuit, Electrolytics near the
circuit B+ to ground would cause top fold over,
While Electrolytics near ground potential to ground would cause bottom
linearity problems.



My 17 inch CRT sometimes gets ...

light-colored horizontal lines
a couple of inches above the bottom of the screen
usually just one or two of these
the picture size too *sometimes* seems to get a tiny bit smaller
when these lines are present.

I have tracked this down to the signal lead going from PC to monitor.

This d*mn lead seems quite sensitive because slight kinks and bends
in the lead can create this effect. So can gently moving the plug as
it goes into the video card. Why can't they design a better lead
than this? It is already the most inflexible lead on my whole
system!

MY QUESTION IS ... is this lead usually as sensitive as this or is it
related to the design of my particular monitor and PC interface.

Can I do anything to improve the situation? I have lowered the
screen refresh rate a bit but that doesn't seem to have help.

Is there a "magic bullet" like something to clip onto the leqad or
some screening.

Changing the lead means some tricky messing around inside the monitor
to terminate the leads it in the screened cage sitting on the cathode
parts of the CRT itself.

Any ideas?

Jon


[Please don't say buy a secondhand 17inch monitor for next to nothing
because cleaning it and dusting out its internals to sharpen up the
image and all that stuff takes time, and so does fetching a checking
over monitors which turn out to be crap.]

 

[meow2222]

Hi Jon

As electronic equipment gets older, the Electrolytics begin to fail, the ESR
begins to rise.
A failing Electrolytic would cause top fold over.
If you look at a typical vertical drive circuit, Electrolytics near the
circuit B+ to ground would cause top fold over,
While Electrolytics near ground potential to ground would cause bottom
linearity problems.

a novel explanation.

Lytics are always suspects, but I wouldnt give them too hard a time.
All but one of the lytics on my 1930s radio are still fine.


NT

 

[t.hoehler]

a novel explanation.

Lytics are always suspects, but I wouldnt give them too hard a time.
All but one of the lytics on my 1930s radio are still fine.


NT
That may be true, but today's lytics are driven pretty hard, especially in
switchers and vert output sections. It's also based on the quality of the
lytic.

My bench service on home entertainment goods shows an awful lot of dried up
lytics, and bad solder joints. With rohs, I suspect the latter will become
even more problematic.
regards,
tom

 

[Jon D]

The admission by the OP of being a troll, in plain sight, and nobody
noticed!

I am the OP.

Guess you haven't read this thread earlier this year in
sci.electronics.components

http://tinyurl.com/jftyr
"Any value in cleaning inside old monitor?"

Many were skeptical like you. But the most convincing answers came from
those who knew there was a value in doing this and I think they were the
majority.


EXTRACTS ...

keeping components hotter than they would be if running in
"free air" conditions.

Not only does it have the chance of getting onto circuitry, it also
changes the capacitance of the tube wall, changing the circuit for the
CRT drive elements as well.


The collection of dust, and much of that moistened at
some point makes for a leaky anode supply and feed wire at the very
least. That makes for poor or shifted focus settings, and other
problems that less than your average video afficianado won't notice.

Most folks rarely notice their focus shifting as well. One has to be
video oriented to notice such things.

Just to back the pro cleaning side, when I made my living from servicing
monitors (and before that TVs) every once in a while I'd get one on the
bench with the safety shutdown tripping because of a buildup of crap
around the anode connector or other HV parts, but then I've also had
nearly as many repairs in that people had damaged cleaning the inside
when they didn't know what they were doing!

 

[kony]

I am the OP.

Guess you haven't read this thread earlier this year in
sci.electronics.components

http://tinyurl.com/jftyr
"Any value in cleaning inside old monitor?"

Many were skeptical like you. But the most convincing answers came from
those who knew there was a value in doing this and I think they were the
majority.

Nope, they did what most do, made random theories about what
hypothetical advantage there might be, without any real
evidence to support the theories. Let's suppose it did help
a particular monitor, is that then evidence it is going to
help most of them? No.

Further we'd first need to know how old the monitor is (is
it even worthwhile), how much crud accumulation there was,
and a measured deviation from appropriate operational
values. Of course it's not good to let parts overheat, or
conduct along unintended paths... but what remains is
actually having that happen. A monitor so poorly designed
that it can't stand a little bit of dust may not be worth
the effort, and one buried in dust might only be a sign of
the real problem- the room needs better air cleaning
equipment, instead of individually cleaning out every part
over and over again.

EXTRACTS ...

keeping components hotter than they would be if running in
"free air" conditions.

Not only does it have the chance of getting onto circuitry, it also
changes the capacitance of the tube wall, changing the circuit for the
CRT drive elements as well.


The collection of dust, and much of that moistened at
some point makes for a leaky anode supply and feed wire at the very
least. That makes for poor or shifted focus settings, and other
problems that less than your average video afficianado won't notice.

Most folks rarely notice their focus shifting as well. One has to be
video oriented to notice such things.

Just to back the pro cleaning side, when I made my living from servicing
monitors (and before that TVs) every once in a while I'd get one on the
bench with the safety shutdown tripping because of a buildup of crap
around the anode connector or other HV parts, but then I've also had
nearly as many repairs in that people had damaged cleaning the inside
when they didn't know what they were doing!

What good does it do to only provide "extracts" that support
your biased opinion? Here's one you left out:

On 3 Apr 2006, <Sam Goldwasser > wrote:

If you're obsessive-compulsive and have nothing better to
do, by all
means clean the insides of your CRT equipment. But it's
probably more
likely that something will get messed accidentally, than any
significant
improvement in either performance or life span.


The high voltage area of modern CRT equipment is generally
enclosed and
or sealed with HV grease or adhesive. It's not like old
all-tube-type
TVs where everything collected an inch of dust if you turned
your back.


Yes, dust does collect. And yes in principle that may
affect something
eventually. But if there are no symptoms, leave it alone.

 

[Jon D]

Nope, they did what most do, made random theories about what
hypothetical advantage there might be, without any real
evidence to support the theories. Let's suppose it did help
a particular monitor, is that then evidence it is going to
help most of them? No.

Further we'd first need to know how old the monitor is (is
it even worthwhile), how much crud accumulation there was,
and a measured deviation from appropriate operational
values. Of course it's not good to let parts overheat, or
conduct along unintended paths... but what remains is
actually having that happen. A monitor so poorly designed
that it can't stand a little bit of dust may not be worth
the effort, and one buried in dust might only be a sign of
the real problem- the room needs better air cleaning
equipment, instead of individually cleaning out every part
over and over again.

I did what that thread suggested and I got a pleasant surprise in the
improved focus.

Maybe my monitor is shite.

Maybe my room is shite.

But that's my monitor and that's my room. And that what I have to
deal with. A good de-dusting works nicely.

What good does it do to only provide "extracts" that support
your biased opinion? Here's one you left out:

I am glad to see you went to the thread and look through it. Well
done.

OTOH my extracts were for those folks who are sort of 50:50 undecided
about checking that thread out. So I posted a random selection of
extracts to show its relevance in the hope that the 50:50 readers
would go and look.

Hey! I did write, "Many were skeptical".