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" <terrypin@dial.pipex.com> wrote in message
news:mkdnn3hnk5qri353op5i5u4e2jra2flfnj@4ax.com...
> 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, East Grinstead, UK
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 t****soid, 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.
In article <mkdnn3hnk5qri353op5i5u4e2jra2flfnj@4ax.com>, Terry Pinnell
<terrypin@dial.pipex.com> writes
>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.
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.
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?
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.
On Thu, 3 Jan 2008 06:22:12 +0000, Mike Tomlinson
<mike@jasper.org.uk> wrote:
>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.
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.
>"Terry Pinnell" <terrypin@dial.pipex.com> wrote in message
>news:mkdnn3hnk5qri353op5i5u4e2jra2flfnj@4ax.com.. .
>> 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, East Grinstead, UK
>
>
>
>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 t****soid, 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.
>
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
_____
"Terry Pinnell" <terrypin@dial.pipex.com> wrote in message
news:mkdnn3hnk5qri353op5i5u4e2jra2flfnj@4ax.com...
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 wrote:
>> 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?
>
>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.
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.
On Thu, 03 Jan 2008 11:16:21 +0000, Terry Pinnell
<terrypinDELETE@THESEdial.pipex.com> wrote:
>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.
>
?? 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.
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?)
Yes that monitor typically cost a lot more than £117 though
I couldn't give an average for your location.
>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.
>
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.
Monitor distortion 
Linear Mode
