Sony GDM-F520 diagonal lines troubleshooting

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I have a 21" Sony monitor and about 7 thin diagonal lines have appeared
on my screen. The look like faint aperture grille lines, but are
angled upward starting at the bottom left. It gives the monitor a
"Candy-Cane" appearance. They do not go away when the monitor is
disconnected from the computer, or with degausing.

Any ideas of what has gone bad?

Approximate cost range to repair this?

I've spent quite a bit of time searching for clues to this problem so
any input would be greatly appreciated.

 

[JANA]

I cannot tell you the exact parts in your monitor. There are many components
that can cause this. The fault is most likely in the vertical blanking
circuits, or in the feedback section of the vertical amplifier section
(causing a vertical blanking phase error). If the vertical blanking drive is
not properly biasing off the CRT during retrace, these lines will be
visible.

Another cause is that the CRT can be going weak, and thus not properly
responding to the blanking bias during the retrace period.

The expensive part of this type of repair is the labour, unless the CRT is
defective. The tech can easily spend more than an hour or two to
troubleshoot for the defective components, and then have to change them.

If you look at the labour cost per hour in your area, this should give you a
good idea of the basic cost for servicing your monitor. Calculate this based
on 2 hours to be safe. As for the parts, if it is a number of small
electrolytic capacitors, the parts cost can be from about $3.00 to $20.00
depending on the amount and the types of capacitors.

In most shops where we are, this would cost about $80 to $140 average, as
said, depending on the exact nature of the fault. This is considering that
the parts involved are also as mentioned.

In my opinion, since I know of this model of monitor, I would be considering
a new monitor. After servicing it, if you consider the age, there is the
potential reliability factor to consider.

A 19 inch LCD pane. would be equivalent to about a 21 inch CRT monitor.
There are many advantages of an LCD screen over a CRT monitor. One of the
main things I like about the LCD monitors, is that there are no convergence
or purity errors.

With LCD monitors, there is no eyesore caused by the scanning electron beam,
and the UV emissions from the screen surface. These monitors are considered
much healthier for the users. If a woman is pregnant there is no worry from
any electromagnetic radiation, or X-Ray emissions. LCD monitors typically
draw about 1/3 to 1/4 of the power consumption, and have no high voltage, as
like in a CRT monitor.

The prices of the LCD monitors are lower than that of the equivalent CRT
monitors of only a small number of years ago.

 

[Rick]

In my opinion, since I know of this model of monitor, I would be considering
a new monitor. After servicing it, if you consider the age, there is the
potential reliability factor to consider.

A 19 inch LCD pane. would be equivalent to about a 21 inch CRT monitor.
There are many advantages of an LCD screen over a CRT monitor. One of the
main things I like about the LCD monitors, is that there are no convergence
or purity errors.

Uh, yeah, and color gamut on LCDs absolutely SUCK,
especially compared to a Sony F520.

 

[Wayne]

I believe you are seeing retrace lines, which means the brightness
level is too high even if set to zero. If this is the case Sony DAS
must be used to correct, or a hardware mod can be done.

First you should try the 'Image Restoration' available in your OSD
menus. Note that the monitor must be powered on for at least 30
minutes, without going into power save mode, for this option to be
available. Often this is all that is needed.

If this is not an option, or does not do the job, see the thread re
the Dell P1130 (same Sony CR1 chassis as your monitor) here
http://www.network54.com/Forum/thread?forumid=87612&messageid=1109559823

A resistor change could correct your problem. See the post at the end
of the thread, below...
"On the main board is a circuit like the P1110, I change the resistor
R941 22M Ohms to 16.8M, this gives 500 Volts on G2,
and I get a good brightness."

Wayne

 

[David S.]

Thanks to everyone for their reply. Wayne, the "Image Restoration"
worked perfectly while making me feel really stupid that it could be
something so simple.

 

[pranza]

Not only a color gamut, but the viewing angle and even with slightly
changed angle when you still see things, the colors change. LCD is good
when you don't need colors nor proper shades even of black and white.
Just for reading text, CAD drawings. Colors on LCDs are fictitious and
refresh is low (about 60-70Hz).
But absence of X rays, flickering and lower power consumption is a good
point that justifies LCD