Question about Sony GDM-C520K (Dark Gray, Gray) 21" CRT Monitor

2 Answers

Fuzzy, unstable display

For a few weeks there was an occasional pop and the sound of static discharge on the CRT surface. Yesterday the sharpness softened for a few minutes but returned. Today the display has become almost too fuzzy to read writing, and unstable. Occasionally it comes into focus for a minute. This AM a tap on the left rear side brought it back, but didn't last. I tried de gaussing to no avail. Display is a little less than 3 yrs old.
Richard Ferrar & Yvonne Muller or bellvale@optonline on the fuzzy monitor

Posted by on

2 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 19 Answers
Re: Fuzzy, unstable display

Sounds like internal arcing, if whacking the monitor had some effect it confirms a probable loose connection, check where the video board plugs into the back of the CRT. this board can become loose, also soldering joins around the flyback transformer may also cause this fault. a common problem in a lot of monitors.

Posted on Apr 26, 2008

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert who has written 50 answers of more than 400 characters.


    An expert whose answer got voted for 20 times.

  • Expert
  • 139 Answers
Re: Fuzzy, unstable display

This sounds like a high-voltage power supply problem, which would need to be diagnosed by an experienced computer or electronics technician.

Check to see if there is a small focus knob on the back. If so try turning it back and forth three or four times to "clean" it....then adjust for correct focus.

Symptoms like this can also be caused by accumulated dust inside the monitor.

Posted on Jan 15, 2008

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

1 Answer

Now in this morning when I on my computer the display of monitor blinks whitely and spread it all screan area.what'sthe problem and how can I solve it?

its due to the discharging of high voltage 2 de ground through the pic tube surface, first u must discharge de eht knobe , clean suface well,
apply sparking preventer ( gel available in all electronic shops) reconnect knob it will be ok

Oct 24, 2009 | Samsung SyncMaster 551 15" CRT Monitor

2 Answers

Screen flashes and sides squeeze in and out

If this is a CRT, then the horizontal deflection circuit is faulty.
The repair is generally not worth on CRT.

First try leaving monitor power cord unplugged for few hours, to discharge capacitors, sometimes this can fix minor problems.

Test also the display on different computers, you never know that this depends from a faulty video adapter.

More likely you will need to replace the screen.

Jul 02, 2009 | ViewSonic A70f 17" CRT Monitor

1 Answer

Samsung 15' sync master monitor

It's seems you got a busted backlight inverter. Need to replaced a new one or repaired it...

Dec 01, 2008 | Samsung SyncMaster 551 15" CRT Monitor

1 Answer

Heard pop sound, then no power

Sounds like your monitor just fried itself.
Since monitors are hazardous, tricky to fix, and are quickly outdated within a year, by a monitor with a bigger size and resolution.

To answer your question: Your monitor is bricked, and will need to be replaced with a new monitor.

Nov 10, 2008 | Medion MD 7317 17" Flat Panel LCD Monitor

1 Answer

ViewSonic VA550 problem with horizontal blurryness

try resetting the settings from the menu ....

if the sharpness or the brightness is high you may feel fuzzyness ..

and also just have a check is there any magnetic field placed near by the monitor if so take it some what away and then give deguass option ....

thank you
any doubts you can reply me
i am always here to assist you
please rate my solution

Aug 29, 2008 | ViewSonic VE155b 15" LCD Monitor

1 Answer

Acer Monitor Display of text and image is not sharp

This might seem obvious, but is your video card output set to the native resolution on the monitor? If not, it will look fuzzy. Try 1680x1050, if you don't know the monitors native resolution.
No need to use anything higher than a 60hz refresh rate either.

Mar 29, 2008 | Acer AL2216WBD LCD Monitor

1 Answer

Vertical lines, colors not sharp, graphics fuzzy

could be the vga car4d problem, try to hook up with another pc if the problem remains then unfortunately the monitor is dying.

Jan 06, 2008 | Envision EN-7100e 17" Flat Panel LCD...

1 Answer

Words are not clear

if its a crt monitor dump it,if its a lcd monitor try changing your screen resolution from display properties,or on the monitor check the brightness and contrast controls.

Dec 26, 2007 | Hyundai ImageQuest L70S 17" LCD Monitor

1 Answer

Intermittent Display

if you have the skill for take off the cover,take off the metal shield and cables until you reach the board,have a 100watt light on,a solder hot iron in one hand and a few rings of tin in the other, obviously take off the plug and left it over a few meters,and waited a few minutes to give some capacitors discharge time,'s easy !!! resolder the joints that like dark,mainly see the big transistors,(or IC)that have like rings on it's pins, and thats all. I tell you its easy okay then you have to "rebuild" your monitor back.don't make shorts pleeease.

Oct 22, 2006 | SAMTRON 55V 15" CRT Monitor

Not finding what you are looking for?
Sony GDM-C520K (Dark Gray, Gray) 21" CRT Monitor Logo

101 people viewed this question

Ask a Question

Usually answered in minutes!

Top Sony Computer Monitors Experts

Cindy Wells

Level 3 Expert

4722 Answers

Lala Alonsi
Lala Alonsi

Level 2 Expert

56 Answers

ray gallant

Level 3 Expert

34675 Answers

Are you a Sony Computer Monitor Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides