Sony monitor interference mystery
 

I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.
Not sure of the chassis number, but inside the case there's a sticker with a
few numbers:

SCC-L45B-A
SV-3614(U)
J505279
6000101

The issue is a shimmering rainbow effect on vertical black lines. I first
noticed it around black text on white backgrounds, where there would be
sections of text with red, green, or bluish shadows around them. I've since
found a test pattern program (ntest.exe) that will put solid vertical lines
on the screen (alternating light and dark), which shows the pattern quite
vividly. It's apparent in any resolution and refresh rate.

I have two pictures at this URL:

http://www3.ns.sympatico.ca/pmason/sony

I took the monitor to a local Sony-authorized shop. Before I left it with
them, I had them run the same test pattern using the same program, and the
image over there was perfectly clean looking!
We tried to increase the refresh rates/resolution, but he was having trouble
getting his computer to cooperate so I left it with him to try and figure
out.
Today he called to say he'd run it up to 1600x1200 at 85 hz, and not seen
any signs of what I described. He suggested I try powering the monitor with
a UPS, so I picked up a UPS from work, and brought the monitor home.

I connected my laptop (running on battery) to the monitor, which was plugged
into the UPS (which was running totally on battery, unplugged from the
wall), and the interference was there. I moved it around the house,
upstairs and down, and got no change. I even hauled it out to the car, with
the UPS, and drove around the block with it running, all with no change! I
did notice however that my signal light had an effect on the pattern,
causing it to shift slightly every time the lights came on. Also, when I
rotate the screen left or right, every x number degrees of rotation will
cause the pattern to jump in one direction or another.

Does this sound like some nasty EM field in my neighborhood? I can't think
of anything else that would cause this. My only other idea was to take the
monitor into work when I'm off vacation next week, and try it there. We are
not too far from the repair shop in the same industrial park Other than
that I am out of ideas!

Anybody have any other thoughts as to what the problem might be?

FWIW. I have another monitor, a 19" Viewsonic, that always has had a slight
shake at the edges of the screen. Similar in frequency to the shimmering of
the interference on the Sony. I ran the test pattern on this monitor, and
there is a similar effect, but not nearly as intense... and mosly limited
to edge of the screen. Until now I never gave it much though, it was a
refurbished monitor, but now it seems like it could be related.

Maybe the Sony is just particularly sensitive to EM fields?

Bring another computer into your house and try the monitor with it.
I'll bet you don't see the problem.

This is classic moire, and can be caused by anything from running
at too high a resolution/refresh rate to (in your case) video circuitry
that's placed too close to other components in a laptop or desktop.

"JM" wrote in message ...
I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.
Not sure of the chassis number, but inside the case there's a sticker with a
few numbers:

SCC-L45B-A
SV-3614(U)
J505279
6000101

The issue is a shimmering rainbow effect on vertical black lines. I first
noticed it around black text on white backgrounds, where there would be
sections of text with red, green, or bluish shadows around them. I've since
found a test pattern program (ntest.exe) that will put solid vertical lines
on the screen (alternating light and dark), which shows the pattern quite
vividly. It's apparent in any resolution and refresh rate.

I have two pictures at this URL:

http://www3.ns.sympatico.ca/pmason/sony

I took the monitor to a local Sony-authorized shop. Before I left it with
them, I had them run the same test pattern using the same program, and the
image over there was perfectly clean looking!
We tried to increase the refresh rates/resolution, but he was having trouble
getting his computer to cooperate so I left it with him to try and figure
out.
Today he called to say he'd run it up to 1600x1200 at 85 hz, and not seen
any signs of what I described. He suggested I try powering the monitor with
a UPS, so I picked up a UPS from work, and brought the monitor home.

I connected my laptop (running on battery) to the monitor, which was plugged
into the UPS (which was running totally on battery, unplugged from the
wall), and the interference was there. I moved it around the house,
upstairs and down, and got no change. I even hauled it out to the car, with
the UPS, and drove around the block with it running, all with no change! I
did notice however that my signal light had an effect on the pattern,
causing it to shift slightly every time the lights came on. Also, when I
rotate the screen left or right, every x number degrees of rotation will
cause the pattern to jump in one direction or another.

Does this sound like some nasty EM field in my neighborhood? I can't think
of anything else that would cause this. My only other idea was to take the
monitor into work when I'm off vacation next week, and try it there. We are
not too far from the repair shop in the same industrial park Other than
that I am out of ideas!

Anybody have any other thoughts as to what the problem might be?

FWIW. I have another monitor, a 19" Viewsonic, that always has had a slight
shake at the edges of the screen. Similar in frequency to the shimmering of
the interference on the Sony. I ran the test pattern on this monitor, and
there is a similar effect, but not nearly as intense... and mosly limited
to edge of the screen. Until now I never gave it much though, it was a
refurbished monitor, but now it seems like it could be related.

Maybe the Sony is just particularly sensitive to EM fields?

Well, I have tried it on another PC, and on my laptop. Both at the lowest
resolution and refresh rates possible. I will try it in a 3rd PC next
week at work, but surely it shouldn't be that prevalent a problem inside
this many PC's?!

"Pete R" wrote in message
ink.net...
Bring another computer into your house and try the monitor with it.
I'll bet you don't see the problem.

This is classic moire, and can be caused by anything from running
at too high a resolution/refresh rate to (in your case) video circuitry
that's placed too close to other components in a laptop or desktop.

"JM" wrote in message
...
I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P
monitor.
Not sure of the chassis number, but inside the case there's a sticker
with a
few numbers:

SCC-L45B-A
SV-3614(U)
J505279
6000101

The issue is a shimmering rainbow effect on vertical black lines. I
first
noticed it around black text on white backgrounds, where there would be
sections of text with red, green, or bluish shadows around them. I've
since
found a test pattern program (ntest.exe) that will put solid vertical
lines
on the screen (alternating light and dark), which shows the pattern
quite
vividly. It's apparent in any resolution and refresh rate.

I have two pictures at this URL:

http://www3.ns.sympatico.ca/pmason/sony

I took the monitor to a local Sony-authorized shop. Before I left it
with
them, I had them run the same test pattern using the same program, and
the
image over there was perfectly clean looking!
We tried to increase the refresh rates/resolution, but he was having
trouble
getting his computer to cooperate so I left it with him to try and
figure
out.
Today he called to say he'd run it up to 1600x1200 at 85 hz, and not
seen
any signs of what I described. He suggested I try powering the monitor
with
a UPS, so I picked up a UPS from work, and brought the monitor home.

I connected my laptop (running on battery) to the monitor, which was
plugged
into the UPS (which was running totally on battery, unplugged from the
wall), and the interference was there. I moved it around the house,
upstairs and down, and got no change. I even hauled it out to the car,
with
the UPS, and drove around the block with it running, all with no change!
I
did notice however that my signal light had an effect on the pattern,
causing it to shift slightly every time the lights came on. Also, when
I
rotate the screen left or right, every x number degrees of rotation will
cause the pattern to jump in one direction or another.

Does this sound like some nasty EM field in my neighborhood? I can't
think
of anything else that would cause this. My only other idea was to take
the
monitor into work when I'm off vacation next week, and try it there. We
are
not too far from the repair shop in the same industrial park Other than
that I am out of ideas!

Anybody have any other thoughts as to what the problem might be?

FWIW. I have another monitor, a 19" Viewsonic, that always has had a
slight
shake at the edges of the screen. Similar in frequency to the
shimmering of
the interference on the Sony. I ran the test pattern on this monitor,
and
there is a similar effect, but not nearly as intense... and mosly
limited
to edge of the screen. Until now I never gave it much though, it was a
refurbished monitor, but now it seems like it could be related.

Maybe the Sony is just particularly sensitive to EM fields?

It looks like Moray effect from the aperture grill (lines) beating against
the scan lines. Does the effect vary when you move the centring, height, or
other scan parameters?

If the beam focus is slightly off its proper setting, it is possible to have
these lines emphasized. The focus performance can change with the aging of
the CRT, or something has changed in the focus supply from the HV
multiplier.

As for black shadows on the edges of highlighted lines, this can be caused
by capacitors that have drifted off value, or the CRT is going a little
weak. The shadows are caused by the effective video low frequency response
being rolled off a little.

--

JANA
_____


"JM" wrote in message
...
I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.
Not sure of the chassis number, but inside the case there's a sticker with a
few numbers:

SCC-L45B-A
SV-3614(U)
J505279
6000101

The issue is a shimmering rainbow effect on vertical black lines. I first
noticed it around black text on white backgrounds, where there would be
sections of text with red, green, or bluish shadows around them. I've since
found a test pattern program (ntest.exe) that will put solid vertical lines
on the screen (alternating light and dark), which shows the pattern quite
vividly. It's apparent in any resolution and refresh rate.

I have two pictures at this URL:

http://www3.ns.sympatico.ca/pmason/sony

I took the monitor to a local Sony-authorized shop. Before I left it with
them, I had them run the same test pattern using the same program, and the
image over there was perfectly clean looking!
We tried to increase the refresh rates/resolution, but he was having trouble
getting his computer to cooperate so I left it with him to try and figure
out.
Today he called to say he'd run it up to 1600x1200 at 85 hz, and not seen
any signs of what I described. He suggested I try powering the monitor with
a UPS, so I picked up a UPS from work, and brought the monitor home.

I connected my laptop (running on battery) to the monitor, which was plugged
into the UPS (which was running totally on battery, unplugged from the
wall), and the interference was there. I moved it around the house,
upstairs and down, and got no change. I even hauled it out to the car, with
the UPS, and drove around the block with it running, all with no change! I
did notice however that my signal light had an effect on the pattern,
causing it to shift slightly every time the lights came on. Also, when I
rotate the screen left or right, every x number degrees of rotation will
cause the pattern to jump in one direction or another.

Does this sound like some nasty EM field in my neighborhood? I can't think
of anything else that would cause this. My only other idea was to take the
monitor into work when I'm off vacation next week, and try it there. We are
not too far from the repair shop in the same industrial park Other than
that I am out of ideas!

Anybody have any other thoughts as to what the problem might be?

FWIW. I have another monitor, a 19" Viewsonic, that always has had a slight
shake at the edges of the screen. Similar in frequency to the shimmering of
the interference on the Sony. I ran the test pattern on this monitor, and
there is a similar effect, but not nearly as intense... and mosly limited
to edge of the screen. Until now I never gave it much though, it was a
refurbished monitor, but now it seems like it could be related.

Maybe the Sony is just particularly sensitive to EM fields?

"JANA" wrote in message
...
It looks like Moray effect from the aperture grill (lines) beating against
the scan lines. Does the effect vary when you move the centring, height,
or
other scan parameters?

It does, but it also varies if I swivel the monitor left or right. This
makes me think it's something external influencing the beam.

If the beam focus is slightly off its proper setting, it is possible to
have
these lines emphasized. The focus performance can change with the aging of
the CRT, or something has changed in the focus supply from the HV
multiplier.

But the effect was totally gone when at the shop...

As for black shadows on the edges of highlighted lines, this can be caused
by capacitors that have drifted off value, or the CRT is going a little
weak. The shadows are caused by the effective video low frequency response
being rolled off a little.

There are no black shadows around anything. There *are* shadows of red,
green, or blue depending on which section of the screen you are looking.
They appear around black text on a white background, and they correspond to
the pattern mentioned above. I'm sure it's just the same problem but only
visible where black borders on white.

JM wrote:
I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.

You have tried all the user-accessible adjustments on the monitor, right?

FWIW, about ten years ago I bought a new computer with a 17" Trinitron
monitor. In the setup section, the user manual mentioned that if you
couldn't get the picture adjusted exactly the way you wanted it, it
might be due to the Earth's magnetic field. It suggested placing the
monitor with the screen facing east (I think) to see if that helped any.
This somewhat agrees with your observation that the display changes when
you swivel the monitor.

You might try moving the monitor to other places in your home. At first,
face it the same direction as it usually faces, then try pointing it
different directions. If you still get the interference in its usual
position, which then changes or goes away in other positions, then it may
well be because of the Earth's magnetic field. If the interference goes
away completely in a certain location, figure out what's different about
that location.

If you're in an apartment, check that your neighbors haven't started a
motor rewinding shop or mail-order magnet supply house out of their
apartments.

Matt Roberds

wrote in message
news:qLpNe.3457$Sj1.2273@okepread04...
JM wrote:
You might try moving the monitor to other places in your home. At first,
face it the same direction as it usually faces, then try pointing it
different directions. If you still get the interference in its usual
position, which then changes or goes away in other positions, then it may
well be because of the Earth's magnetic field. If the interference goes
away completely in a certain location, figure out what's different about
that location.

Yeah, I moved it all around the house; and tried it facing all different
directions... I even took it around the block in the car. A friend of mine
wondered if there was a HAM radio operator in the area, which I guess is
possible...

If you're in an apartment, check that your neighbors haven't started a
motor rewinding shop or mail-order magnet supply house out of their
apartments.

Heheh yeah I'm in my own house but I wouldn't be surprised if someone's got
a particle accelerator or something in their basement... that would explain
the silverware sticking to my forehead all the time ;)

I'm taking it to work next week so that will be the real test.

try a different scan rate..

why does it worek ok at the Sony shop..

what is dfferent there?

Do you have an AM radio station near your house?

You see the intereference in your car? What if you drive to the Sony
shop?

Mark

why does it worek ok at the Sony shop..

what is dfferent there?

That is the question that needs to be asked.
The picture looks like either moire interference caused by too high of
scan rate for the aperature grill in the picture tube or a video
bandwidth problem.

If it really does work perfect on the test setup at the service shop,
then it stands to reason that it is some part of the equipment that did
not go to the shop. Did the video cable go with the monitor? Did the
computer go with the monitor?

I am guessing that it is an el-cheapo video card problem where the card
has a bandwidth problem or other issue.

JM wrote: A friend of mine
wondered if there was a HAM radio operator in the area, which I guess is
possible...


Most HAM Radio operators cause no interference to anyone's electronics
in their neighborhood. We follow strict guidelines in regards to RFI
and try to maintain our equipment to not cause anyone problems.
Also the problems you describe don't sound like they are being caused by
RF interference.

KB2ZWO

"Mark" wrote in message
ps.com...
try a different scan rate..

It's the same regardless of scan rate.

why does it worek ok at the Sony shop..
what is dfferent there?

Wish I knew.

You see the intereference in your car? What if you drive to the Sony
shop?

Well, I'll be taking it to work next week, which is fairly close to the
shop. If it does it there, then maybe I'll drive to the shop with it hooked
up in the car and see if it continues to do it when I get there. If so
it'll be pretty hard for them to deny its existence :)

wrote in message
oups.com...
why does it worek ok at the Sony shop..
what is dfferent there?
That is the question that needs to be asked.
The picture looks like either moire interference caused by too high of
scan rate for the aperature grill in the picture tube or a video
bandwidth problem.

Well I'm fairly confident I'll know much better once I get the monitor away
from this area and, if necessary, in my car outside the repair shop.

If it really does work perfect on the test setup at the service shop,
then it stands to reason that it is some part of the equipment that did
not go to the shop. Did the video cable go with the monitor? Did the
computer go with the monitor?

The video cable did, the computer did not, but the video card is a Leadtek
Geforce 6600, and I had the same symptoms with a Geforce 4 ti 4200 before
that.
The shop computer was a Geforce FX 5200 or something like that.

Also, the problem exists when my laptop is connected, and when a third PC is
connected. My desktop runs a 450 watt PSU (with only one hard drive, 1 gig
of RAM and a CPU to power) and I have an Asus A7N8X motherboard. Shouldn't
be anything there that would cause problems.

"Jumpster Jiver" wrote in message
news:xJyNe.4090$_f.1902@trnddc03...
JM wrote: A friend of mine
wondered if there was a HAM radio operator in the area, which I guess is
possible...
Most HAM Radio operators cause no interference to anyone's electronics
in their neighborhood. We follow strict guidelines in regards to RFI
and try to maintain our equipment to not cause anyone problems.

That was my thought, if that wasn't the case then there would be all kinds
of reports of interference from HAM radios and what not.

Also the problems you describe don't sound like they are being caused by
RF interference.

I agree, to me it looks more like an EM field in the area. Especially
considering how the pattern changes as I rotate the monitor...

I'm starting to wonder if maybe *I* am giving off a magnetic field...

I ask agaqin...is there an AM radio station transmitter in your
area...i.e big towers?

Mark

"Mark" wrote in message
oups.com...
I ask agaqin...is there an AM radio station transmitter in your
area...i.e big towers?

Not in my immediate area, no.. I'm in the suburbs so there's nothing like
that too close. A few cell towers within a 2-3 km radius I would say, but
that's pretty common anywhere these days I'm sure.

1. Possibly the aperature grill is miasaligned due to the unit falling.
2. Do you live near a medical facility with an MRI machibe?
3. Magnetic field due to wiring in your walls.

JM wrote:

I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.
Not sure of the chassis number, but inside the case there's a sticker with a
few numbers:

SCC-L45B-A
SV-3614(U)
J505279
6000101

The issue is a shimmering rainbow effect on vertical black lines. I first
noticed it around black text on white backgrounds, where there would be
sections of text with red, green, or bluish shadows around them. I've since
found a test pattern program (ntest.exe) that will put solid vertical lines
on the screen (alternating light and dark), which shows the pattern quite
vividly. It's apparent in any resolution and refresh rate.

I have two pictures at this URL:

http://www3.ns.sympatico.ca/pmason/sony

I took the monitor to a local Sony-authorized shop. Before I left it with
them, I had them run the same test pattern using the same program, and the
image over there was perfectly clean looking!
We tried to increase the refresh rates/resolution, but he was having trouble
getting his computer to cooperate so I left it with him to try and figure
out.
Today he called to say he'd run it up to 1600x1200 at 85 hz, and not seen
any signs of what I described. He suggested I try powering the monitor with
a UPS, so I picked up a UPS from work, and brought the monitor home.

I connected my laptop (running on battery) to the monitor, which was plugged
into the UPS (which was running totally on battery, unplugged from the
wall), and the interference was there. I moved it around the house,
upstairs and down, and got no change. I even hauled it out to the car, with
the UPS, and drove around the block with it running, all with no change! I
did notice however that my signal light had an effect on the pattern,
causing it to shift slightly every time the lights came on. Also, when I
rotate the screen left or right, every x number degrees of rotation will
cause the pattern to jump in one direction or another.

Does this sound like some nasty EM field in my neighborhood? I can't think
of anything else that would cause this. My only other idea was to take the
monitor into work when I'm off vacation next week, and try it there. We are
not too far from the repair shop in the same industrial park Other than
that I am out of ideas!

Anybody have any other thoughts as to what the problem might be?

FWIW. I have another monitor, a 19" Viewsonic, that always has had a slight
shake at the edges of the screen. Similar in frequency to the shimmering of
the interference on the Sony. I ran the test pattern on this monitor, and
there is a similar effect, but not nearly as intense... and mosly limited
to edge of the screen. Until now I never gave it much though, it was a
refurbished monitor, but now it seems like it could be related.

Maybe the Sony is just particularly sensitive to EM fields?





--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"

The Lost Deep Thoughts By: Jack Handey
Before a mad scientist goes mad, there's probably a time
when he's only partially mad. And this is the time when he's
going to throw his best parties.

1. Possibly the aperature grill is miasaligned due to the unit falling.
2. Do you live near a medical facility with an MRI machine?
3. Magnetic field due to wiring in your walls.

JM wrote:

I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.
Not sure of the chassis number, but inside the case there's a sticker with a
few numbers:

SCC-L45B-A
SV-3614(U)
J505279
6000101

The issue is a shimmering rainbow effect on vertical black lines. I first
noticed it around black text on white backgrounds, where there would be
sections of text with red, green, or bluish shadows around them. I've since
found a test pattern program (ntest.exe) that will put solid vertical lines
on the screen (alternating light and dark), which shows the pattern quite
vividly. It's apparent in any resolution and refresh rate.

I have two pictures at this URL:

http://www3.ns.sympatico.ca/pmason/sony

I took the monitor to a local Sony-authorized shop. Before I left it with
them, I had them run the same test pattern using the same program, and the
image over there was perfectly clean looking!
We tried to increase the refresh rates/resolution, but he was having trouble
getting his computer to cooperate so I left it with him to try and figure
out.
Today he called to say he'd run it up to 1600x1200 at 85 hz, and not seen
any signs of what I described. He suggested I try powering the monitor with
a UPS, so I picked up a UPS from work, and brought the monitor home.

I connected my laptop (running on battery) to the monitor, which was plugged
into the UPS (which was running totally on battery, unplugged from the
wall), and the interference was there. I moved it around the house,
upstairs and down, and got no change. I even hauled it out to the car, with
the UPS, and drove around the block with it running, all with no change! I
did notice however that my signal light had an effect on the pattern,
causing it to shift slightly every time the lights came on. Also, when I
rotate the screen left or right, every x number degrees of rotation will
cause the pattern to jump in one direction or another.

Does this sound like some nasty EM field in my neighborhood? I can't think
of anything else that would cause this. My only other idea was to take the
monitor into work when I'm off vacation next week, and try it there. We are
not too far from the repair shop in the same industrial park Other than
that I am out of ideas!

Anybody have any other thoughts as to what the problem might be?

FWIW. I have another monitor, a 19" Viewsonic, that always has had a slight
shake at the edges of the screen. Similar in frequency to the shimmering of
the interference on the Sony. I ran the test pattern on this monitor, and
there is a similar effect, but not nearly as intense... and mosly limited
to edge of the screen. Until now I never gave it much though, it was a
refurbished monitor, but now it seems like it could be related.

Maybe the Sony is just particularly sensitive to EM fields?





--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"

The Lost Deep Thoughts By: Jack Handey
Before a mad scientist goes mad, there's probably a time
when he's only partially mad. And this is the time when he's
going to throw his best parties.

On Thu, 18 Aug 2005 17:34:25 GMT, "JM" put
finger to keyboard and composed:

I've got a bit of a mystery on my hands with my Sony 21" CPD-G520P monitor.

The issue is a shimmering rainbow effect on vertical black lines.

Smack the face of the CRT with your hand. Does the pattern vibrate? If
so, then this would confirm that your problem is related to the
aperture grill.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

"Franc Zabkar" wrote in message
...
Smack the face of the CRT with your hand. Does the pattern vibrate? If
so, then this would confirm that your problem is related to the
aperture grill.

No change at all if I smack on the case, or directly on the screen (as hard
as I felt comfortable doing).

What is around the monitor? Any other electrical equipment?
Maybe a nearby tv set or other device?

wrote in message
oups.com...
What is around the monitor? Any other electrical equipment?
Maybe a nearby tv set or other device?

Well there is a small tv about 4 feet away.. and my pc tower next to the
monitor,but as I said I've moved it all around the house and driven it
around the block... all with no appreciable change in the problem.

Assuming there is not some 50KW transmitting tower within one mile,
what is the ac line voltage reading at your house?

You are allowing the degauss circuit to activate after the unit has
been sitting in each new location off for a while.

wrote in message
oups.com...
Assuming there is not some 50KW transmitting tower within one mile,
what is the ac line voltage reading at your house?

120.5 vac, +/- about .2 volts.

You are allowing the degauss circuit to activate after the unit has
been sitting in each new location off for a while.

Yes, and it has had no effect.

I took the monitor to work today, about 10-15 km away, and the problem was
present there. I'm going to leave it for now until the tech is back from
vacation at the repair shop, and I'm back from my vacation, so it'll be in a
couple of weeks. I'll see if I can bring it by the shop again with my
laptop and double check that it's not happening there... again. I'll take a
UPS with me in the car and run it on battery for the trip over, just in case
it happens to magically clear up somewhere on the trip over.

I'll post the results of that adventure when the time comes :)

Thanks for all the replies in the meantime.

"James Jones" wrote in message
...
JM wrote:
I have two pictures at this URL:
http://www3.ns.sympatico.ca/pmason/sony
Have you tried minimizing the moire pattern by using the moire
adjustment in the user controls?

Yes, and it does help to a point, but it also makes the screen so blurry (I
have to set it to the highest setting) it's not worth using.