monitor noise and lines

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

I have a samsung chassis DP15LT. It worked fine for last two years.
One it starts to give noise and horizontal line from top to bottom of
the screen. If any other monitor is placed near (10 feets) this
monitor, that monitor too affected by this noise and starts horizontal
lines. There seems to be no default in the monitor parts. I doubt the
EHT. Is is correct? how to correct this problem?

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

Check the electrolytic capacitors on the main circuit board.
I had one like this a few days ago. It started with a light grey bar
waving at top then gradually fading out. There was noise in the background
of the screen. It turned out that a 1000Uf/16V capacitor in the power
supply had gone way down in value (to about 50Uf).
Check all the electrolytic caps in the power supply and horizontal/
vertical scan circuits.
John

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

jdgill@juno.com (John Gill) wrote in message news:<71016e83.0405040630.4a71b32e@posting.google.com>...
> Check the electrolytic capacitors on the main circuit board.
> I had one like this a few days ago. It started with a light grey bar
> waving at top then gradually fading out. There was noise in the background
> of the screen. It turned out that a 1000Uf/16V capacitor in the power
> supply had gone way down in value (to about 50Uf).
> Check all the electrolytic caps in the power supply and horizontal/
> vertical scan circuits.
> John

When the power is on, the noise starts and after 3 seconds (when the
monitor goes to the standby) it stops. When the monitor receives v
signal from computer and on the power the noise starts and the
horizontal bar lines appear in the screen.

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

"Adimurugan.V" <avm1@vsnl.com> wrote in message
news:8b06ea55.0405041953.6046e4cd@posting.google.com...
> jdgill@juno.com (John Gill) wrote in message
news:<71016e83.0405040630.4a71b32e@posting.google.com>...
> > Check the electrolytic capacitors on the main circuit board.
> > I had one like this a few days ago. It started with a light grey bar
> > waving at top then gradually fading out. There was noise in the
background
> > of the screen. It turned out that a 1000Uf/16V capacitor in the power
> > supply had gone way down in value (to about 50Uf).
> > Check all the electrolytic caps in the power supply and horizontal/
> > vertical scan circuits.
> > John
>
> When the power is on, the noise starts and after 3 seconds (when the
> monitor goes to the standby) it stops. When the monitor receives v
> signal from computer and on the power the noise starts and the
> horizontal bar lines appear in the screen.

Do you have any idea if it may be the result of magnetic interference into
the display?
Has any magnetic component (fluorescent lamp, transformer, another monitor)
been
recently moved to be nearby the monitor?
If the noise moves slowly through the screen when refresh rate is set for
"mains frequency",
can you try to change the refresh rate and see a different effect? If so, it
is strong evidence
of some type of power line interference - either magnetic, or possible the
internal filtering
capacitors gone, as suggested.

HTH

Not Gimpy Anymore(!)