Monitor distortion

  • Thread starter Thread starter Terry Pinnell
  • Start date Start date
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Terry Pinnell

I've just noticed that circular objects become squashed inwards from
the right, the closer they are to the right hand edge of my screen.
Doesn't happen with top, left or bottom edges to any significant
extent - just the right. Circle looks like a lemon. No magnetic fields
in the vicinity. Degaussed anyway but made no difference.

This is an HP p930 19" CRT monitor. Although a bit apprehensive about
fiddling with its menu geometry options, I did play blindly with some
of them, but so far in vain.

Can anyone help me isolate and fix the problem please?
 
Terry Pinnell said:
I've just noticed that circular objects become squashed inwards from
the right, the closer they are to the right hand edge of my screen.
Doesn't happen with top, left or bottom edges to any significant
extent - just the right. Circle looks like a lemon. No magnetic fields
in the vicinity. Degaussed anyway but made no difference.

This is an HP p930 19" CRT monitor. Although a bit apprehensive about
fiddling with its menu geometry options, I did play blindly with some
of them, but so far in vain.

Can anyone help me isolate and fix the problem please?
Click to expand...



Terry

What you describe is a non linear sweep.
i.e. the electron beam is sweeping across the screen at different speeds
depending on what side of the screen it is at.
(think of the shape of a ski jump)
Geometry Menu options usually cover trapesoid, pincushion, barrel and
parallel distortion not sweep linearity.
Sweep linearity is usually an internal or hidden menu adjustment , as such
you are likely to need the services of a Monitor Technician.

Under those circumstances it may well be cheaper to locate a second hand
replacement, or to look at a new LCD.

Best Luck
Paul.
 
Terry Pinnell <[email protected]>, the debilitated-destitute and
unabashed chocolate starfish poker who likes rough bowel loosening with
camels, and whose partner is a comfort woman with a diseased gooey man
trap said:
I've just noticed that circular objects become squashed inwards from
the right, the closer they are to the right hand edge of my screen.
Doesn't happen with top, left or bottom edges to any significant
extent - just the right. Circle looks like a lemon. No magnetic fields
in the vicinity. Degaussed anyway but made no difference.

This is an HP p930 19" CRT monitor. Although a bit apprehensive about
fiddling with its menu geometry options, I did play blindly with some
of them, but so far in vain.

Can anyone help me isolate and fix the problem please?
Click to expand...


Why should anyone help you Pinhead?
You refuse to thank a single person for any of the help you have received,
ever.
You're just a thankless **** who deserves all that ****s-up in your life.
Don't bother denying anything there's plenty of evidence available.


--
For my own part, I have never had a thought which I could not set down
in words with even more distinctness than that with which I conceived
it. There is, however, a class of fancies of exquisite delicacy which
are not thoughts, and to which as yet I have found it absolutely
impossible to adapt to language. These fancies arise in the soul, alas
how rarely. Only at epochs of most intense tranquillity, when the
bodily and mental health are in perfection. And at those weird points
of time, where the confines of the waking world blend with the world of
dreams. And so I captured this fancy, where all that we see, or seem,
is but a dream within a dream.
 
Terry Pinnell said:
I've just noticed that circular objects become squashed inwards from
the right, the closer they are to the right hand edge of my screen.
Doesn't happen with top, left or bottom edges to any significant
extent - just the right. Circle looks like a lemon.
Click to expand...

Is this a circle in the centre of the screen or a circle in the top
right hand corner?

If in the centre, that's unusual. Geometry issues caused by menu
controls will have a mirror effect - i.e. both top-and-bottom OR right-
and-left sides of the screen will be affected by any adjustment.
This is an HP p930 19" CRT monitor. Although a bit apprehensive about
fiddling with its menu geometry options, I did play blindly with some
of them, but so far in vain.
Click to expand...

If you can't get a good circle with use of the keystone, parallax or
pincushion controls (see the manual to find out which on-screen menu
icons those correspond to), it's probable that 1) the geometry circuitry
has failed (how old is the monitor?) or less likely, 2) a correction
magnet on the back of the tube has fallen off. Has the monitor been
banged, dropped or moved recently?
Can anyone help me isolate and fix the problem please?
Click to expand...

Toss it and get a nice new TFT?

The p930 came with a 3 year warranty. If it's still in warranty, stick
a claim in. Tell the phone droid the monitor is dead - they may give
you the run around if they perceive it to be a minor picture alignment
issue.
 
The p930 came with a 3 year warranty. If it's still in warranty, stick
a claim in. Tell the phone droid the monitor is dead - they may give
you the run around if they perceive it to be a minor picture alignment
issue.
Click to expand...


yes they might give the runaround. I had an equivalent
Compaq Trinitron tubed monitor that failed under warranty,
shortly after HP took over Compaq's interested, at which
point they gave me that runaround in verifying warranty
rights before they sent a P930. Being a non-sony tube I
wasn't thrilled with the substitution but it worked fine for
a few years then got dimmer and dimmer till the video card
driver tweaks were marginal and it was planned to be
replaced... then when it got colder as winter set on, the
horizonal starting going out and there was rapid wiggling of
everything on-screen.

unfortunately the original compaq warranty was up, but i
prefer LCDs so it was just a nudge in the the right
direction except i'd have liked to get a year or more out of
it... it does seem it died too soon.
 
PeeCee said:
Terry

What you describe is a non linear sweep.
i.e. the electron beam is sweeping across the screen at different speeds
depending on what side of the screen it is at.
(think of the shape of a ski jump)
Geometry Menu options usually cover trapesoid, pincushion, barrel and
parallel distortion not sweep linearity.
Sweep linearity is usually an internal or hidden menu adjustment , as such
you are likely to need the services of a Monitor Technician.

Under those circumstances it may well be cheaper to locate a second hand
replacement, or to look at a new LCD.

Best Luck
Paul.
Click to expand...
Paul, Mike: Thanks both. Looking for documentation right now. But I
may well reconcile myself to living with it until my well-overdue PC
upgrade, when I may treat myself to a 22" or 24" wide screen LCD/TFT.

There is a menu entry called Linearity. But it appears to be affect
'squashing' at top and bottom, not left and right.

Any idea about this one called 'Recall'? It offers just Yes and No.

Mike: As mentioned, image only distorts when it's close to right edge,
whether top, middle or bottom. I used a resized image so that circle
occupies whole window, and I could then drag it around the screen.

Ah - found a Visa entry dated 15th April 2005, so looks like I'm
within the 3 years. Hopefully there's a receipt here somewhere. Visa
shows supplier as 'MCS', and I paid £117.45. (BTW, I'm sure I saw much
higher than prices when I googled yesterday?)
 
If the monitor was good before and over time the problem started to show,
this is an indication of some components failing in the sweep circuitry of
the monitor. This type of failure is not an adjustment. Common failures are
electrolytic capacitors in the related areas. The power supply, and scan
amplifier circuits are usually where most of the failures occur. Capacitors
usually fail from heat and usage.

If the distortion is horizontal where the image is distorted on the right or
left side of the screen, the defect is in the horizontal scan or sweep area.
If the distortion is in the top or bottom direction, the defect is in the
vertical scan or sweep area.

With proper trouble-shooting the defective caps can be located and changed
for new ones. This will take someone who is experienced in monitor
servicing, and have the proper tools and instruments to perform the work.
The main obstacle that the service tech may run in to is if he needs the
service manual and schematics, and any dedicated parts. The manufactures of
most computer monitors will not supply service support to any non-contracted
service tech facilities.

In the end, you may not find the cost of servicing a computer monitor
feasible in relation to replacing it. At today's prices you can have an LCD
screen for a very reasonable cost. Computer monitors are designed for a life
span of about three to four years with normal use. After about 30,000 hours,
they tend to start decreasing in their performance.

--

JANA
_____


I've just noticed that circular objects become squashed inwards from
the right, the closer they are to the right hand edge of my screen.
Doesn't happen with top, left or bottom edges to any significant
extent - just the right. Circle looks like a lemon. No magnetic fields
in the vicinity. Degaussed anyway but made no difference.

This is an HP p930 19" CRT monitor. Although a bit apprehensive about
fiddling with its menu geometry options, I did play blindly with some
of them, but so far in vain.

Can anyone help me isolate and fix the problem please?
 
Terry said:
I've just noticed that circular objects become squashed inwards from
the right, the closer they are to the right hand edge of my screen.
Doesn't happen with top, left or bottom edges to any significant
extent - just the right. Circle looks like a lemon. No magnetic fields
in the vicinity. Degaussed anyway but made no difference.

This is an HP p930 19" CRT monitor. Although a bit apprehensive about
fiddling with its menu geometry options, I did play blindly with some
of them, but so far in vain.

Can anyone help me isolate and fix the problem please?
Click to expand...

Someone in sci.electronics.repair may know how, but also read the FAQ
at www.repairfaq.org. Some libraries have Sams Photofacts repair
manuals, on paper or online.

The monitor likely has a dying electrolytic capacitor in its
horizontal sweep circuit, but an adjustment should fix the picture
well enough for you (it has for me) In older CRT monitors that's done
by turning the slug in a horizontal circuit coil, but newer monitors
handle it digitally, either though a hidden menu or with special
equipment (Samsung's was $600, Panasonic's was homemade for $10 and
required a program they sold for $3). If HP won't tell you how to
bring up any service menu, try to find the actual manufacturer by
reading the UL registration number and looking it up at UL.com. Some
manufacturers, like Envision (AOC) and CTX were very good about
providing technical information to anybody (Envision even sent out
free service manuals by e-mail), while others are paranoid about
consumers electrocuting themselves.

Don't work on the monitor itself unless you have electronics repair
experience, and realize that glass breakage can be much a risk as
electric shock, so do not set the monitor upright on a bed or sofa or
it will fall forward. Instead set it with the screen on the bottom.
Read all the safety precautions in the RepairFaq first.
 
JANA said:
The manufactures of most computer monitors will not supply service
support to any non-contracted service tech facilities.
Click to expand...

Ah, the good old days, pre-2000, when many of them would. CTX laid
off most of its US employees a few years ago, including almost every
technician, and replaced them with lower-cost people who received no
training. Despite that, many of them were awarded the title
"technician," and one of them almost cried when they couldn't answer
some very basic questions about monitors. Even Japanese companies
that were once known for excellent service went that way, such as
Panasonic. When I asked one of their monitor "technicians" about a
user control for the convergence, the reply was, "I don't know what
convergence are." The manager assured me the person was one of their
best technicians.
In the end, you may not find the cost of servicing a computer monitor
feasible in relation to replacing it. At today's prices you can have an LCD
screen for a very reasonable cost.
Click to expand...

Not for the picture quality I want. Movies with dark scenes are
almost unwatchable to me on LCDs because the blacks aren't black
enough, not even with Samsung's multiple backlight system, which is
meant to improve the blacks. So I'm keeping my Farnsworth until
Elvis' ghost shoots the picture tube.
Computer monitors are designed for a life span of about three to
four years with normal use. After about 30,000 hours, they tend
to start decreasing in their performance.
Click to expand...

I still have my NEC Multisync II monitor from about 1985. It still
works well but can't display over 800x600 without interlace.
 
Someone in sci.electronics.repair may know how, but also read the FAQ
at www.repairfaq.org. Some libraries have Sams Photofacts repair
manuals, on paper or online.

The monitor likely has a dying electrolytic capacitor in its
horizontal sweep circuit, but an adjustment should fix the picture
well enough for you (it has for me) In older CRT monitors that's done
by turning the slug in a horizontal circuit coil, but newer monitors
handle it digitally, either though a hidden menu or with special
equipment (Samsung's was $600, Panasonic's was homemade for $10 and
required a program they sold for $3). If HP won't tell you how to
bring up any service menu, try to find the actual manufacturer by
reading the UL registration number and looking it up at UL.com. Some
manufacturers, like Envision (AOC) and CTX were very good about
providing technical information to anybody (Envision even sent out
free service manuals by e-mail), while others are paranoid about
consumers electrocuting themselves.

Don't work on the monitor itself unless you have electronics repair
experience, and realize that glass breakage can be much a risk as
electric shock, so do not set the monitor upright on a bed or sofa or
it will fall forward. Instead set it with the screen on the bottom.
Read all the safety precautions in the RepairFaq first.
Click to expand...

Thanks for the follow-ups.

I was terrifically impressed with the service I had from HP today.
Half an hour ago, only about 4 hours since I first called them, I have
a replacement monitor!

The process was stressful at the outset. Two conversations, apparently
with support staff in India, were cut-off when they tried to transfer
me to 'the right department'. And then my serial number was mapped to
an entirely different HP product - apparently the numbers are not
unique! And then I was told that it was 2 years outside the 3 year
warranty period, despite having a receipt in front of me (for a 'NEW,
BOXED, P930') dated 14th April, 2005. Anyway, within minutes of
emailing them a scan of that, I had confirmation that delivery would
be within 24 hours, and that improved an hour later to today! Finally
arrived at about 7pm (it's 7.30 now).

HOWEVER, unfortunately the story doesn't have a happy ending. The
glass surface of the screen is badly blemished. There's an irregular
mark over an area of about 4cm x 4cm, towards lower left of screen. No
response to cleaning.

Here's a photo, although it's hard to see because of the reflections.
http://www.terrypin.dial.pipex.com/Images/HP-P930-Mark.jpg

I'd rather have the distortion than peering through this ;-(

I reckon I'll be asking for another replacement...
 
Paul, Mike: Thanks both. Looking for documentation right now. But I
may well reconcile myself to living with it until my well-overdue PC
upgrade, when I may treat myself to a 22" or 24" wide screen LCD/TFT.
Click to expand...

?? It's not as though you have to replace the monitor as
same time as rest of system, usually (unless it were
something ancient and the video card and/or it's driver
simply can't support 22-24" wide screen native resolutions.
Then again, I suppose if you were looking for an OEM package
deal that included a monitor then it might save a little
money to buy all at once, but often the deals are for the
lower end monitors in any size and choosing the upgraded
monitor (same size, or larger, it varies) adds enough to the
cost of the system that it might be as well to just find a
good deal on a separate retail monitor.


There is a menu entry called Linearity. But it appears to be affect
'squashing' at top and bottom, not left and right.

Any idea about this one called 'Recall'? It offers just Yes and No.
Click to expand...

Probably resets the defaults, which is certainly something
you should try if you don't mind readjusting the settings
again as you had them previously (if it doesn't solve the
problem, and probably it won't if the monitor had began
distorting like this without any changes to these settings).


Mike: As mentioned, image only distorts when it's close to right edge,
whether top, middle or bottom. I used a resized image so that circle
occupies whole window, and I could then drag it around the screen.

Ah - found a Visa entry dated 15th April 2005, so looks like I'm
within the 3 years. Hopefully there's a receipt here somewhere. Visa
shows supplier as 'MCS', and I paid £117.45. (BTW, I'm sure I saw much
higher than prices when I googled yesterday?)
Click to expand...

Yes that monitor typically cost a lot more than £117 though
I couldn't give an average for your location.
 
On Thu, 3 Jan 2008 09:14:43 -0800 (PST),
Not for the picture quality I want. Movies with dark scenes are
almost unwatchable to me on LCDs because the blacks aren't black
enough, not even with Samsung's multiple backlight system, which is
meant to improve the blacks. So I'm keeping my Farnsworth until
Elvis' ghost shoots the picture tube.
Click to expand...

Seems pretty arbitrary to me... you do realize that in real
life, seldom is anything actually "pitch black", rather
shades above complete blackness? Similarly, just because
you used to see nearer complete black portions in movies it
doesn't necessarily mean that's how they were supposed to
look.

LCDs do of course have higher black level than CRT on
average, but it's not something one can't become adjusted to
rather quickly, so long as the particular LCD doesn't have a
lot of backlight bleeding or irregular lighting. On the
other hand, LCDs have much going for them in that they show
details in (movies, etc) that are blurred on a CRT.
 
Terry Pinnell said:
Paul, Mike: Thanks both. Looking for documentation right now. But I
may well reconcile myself to living with it until my well-overdue PC
upgrade, when I may treat myself to a 22" or 24" wide screen LCD/TFT.
ok.

There is a menu entry called Linearity. But it appears to be affect
'squashing' at top and bottom, not left and right.
Click to expand...

Vertical linearity. There's vertical and horizontal.
Any idea about this one called 'Recall'? It offers just Yes and No.
Click to expand...

It recalls the previous menu settings before you changed them in case
you feck things up.
Mike: As mentioned, image only distorts when it's close to right edge,
whether top, middle or bottom. I used a resized image so that circle
occupies whole window, and I could then drag it around the screen.
Click to expand...

ok. there's problems with horizontal linearity, and if you're not
offered that as a menu option to twiddle, it's an internal adjustment
(not available to the end-user; the insides of monitors have a nasty
bite.)
Ah - found a Visa entry dated 15th April 2005, so looks like I'm
within the 3 years.
Click to expand...

Nice one. I see you got a replacement, hope the replacement of the
replacement is in better condition. :)
 
Terry Pinnell <[email protected]>, the debilitated-destitute and
unabashed chocolate starfish poker who likes rough bowel loosening with
camels, and whose partner is a comfort woman with a diseased gooey man



Why should anyone help you Pinhead?
You refuse to thank a single person for any of the help you have received,
ever.
You're just a thankless **** who deserves all that ****s-up in your life.
Don't bother denying anything there's plenty of evidence available.
Click to expand...

Very productive. Not.

Only one of the things I've seen in my time on Usenet is a creeping
cretinism that automatically assumes it is entitled to behave in any way
that it wants, and to acquite anything it wants on demand. When it is
pressed for reasons substiantiating the need for its cretinism, it remains
true to type. Very stupid, but consistent.
From a medical standpoint we generally classify this kind of patient as DNR
Click to expand...
(Do Not Resuscitate). The only thing you should do in these cases is to
make the patient as comfortable as possible so they won't bother the nurses
with endless complaints. Then, you must move on to the next case and find
out whether your skill is equal to whatever he presents.

Lather, rinse, and repeat. It's no wonder that so many docs get into the
morphine. So far scotch seems to work well enough for me, but I'll know
it's time to retire when I start lingering at the dispensary.


Dr. Beard
 
CBFalconer <[email protected]>, the dirty-minded-hobo and easy
poo-stabber who likes disgraceful backstroke roulette with
hippopotamuses, and whose partner is an amateur with a messy camel hoof,
wrote in said:
... snip worse ...

PLONK.

Chuck F ([email protected])
Click to expand...

****wit.


--
Lunch was nice;
Exposed blow flies accompanied with spoilt English sparrow tail, served
in a splashing pannikin heaped with sickly chunks of cucumber and
hodgepodge of cauliflower in salt water, a side of tree mouse lung and a
goblet of coagulated white blood cells.
 
harikeo spewed out this bit, and i'll scatter a few bits myself:
I think fukwad ends up on most people's KF sooner or later.
Click to expand...

*PLONK*

Nasty mouthed hooligan !

--
Mhzjunkie

1 PRINT "Windows Vista ERROR"
GOTO 1
END
 
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