Shaking / Blurred Monitor

[Dipper]

I have had a reoccuring problem of shaking ,blurring image on my pc ,this doesnt happen all the time and doesnt seem to be related to interference from other electrical devices nearby,Ive used a plug in circuit tester which indicated circuit was ok any ideas of cause and remedies gratefully received

 

[2scoops0406]

Try using another monitor, it could be knackered.

 

[Igorian]

Does it happen more often if the screen has a predominently white or light coloured background?

Any mobile phones/wireless devices nearby?

As Ed suggests, try another monitor or the same monitor on another PC.

 

[Big_Spark]

Igorian can say whether this is likely or not..but have you tried to degausse the monitor? Within the menu controls there should be this option..it may look like a horseshoe magnet with a bolt of lightning through it..

I have been using PCD's for some time now so cannot remember if this was ever a sign of the screen needing degausing..

 

[Igorian]

Igorian can say whether this is likely or not..but have you tried to degausse the monitor? Within the menu controls there should be this option..it may look like a horseshoe magnet with a bolt of lightning through it..

I have been using PCD's for some time now so cannot remember if this was ever a sign of the screen needing degausing..

I was going down the route of HT instability/Defective lopt, hence the question about white / light screens, which tends to cause the raster to break down at the edges in a sort of pulsing movement. Degaussing eliminates magnetism of the CRT, which can be caused by anything from locating speakers too close or even just changing it's orientation. The screen would look blotchy, rather like a bruise, but it wouldn't cause the shakes.

It is possible for the A1 control on the lopt to develop a 'flat spot', which could possibly cause an intermittent fault like the one you describe. Adjusting the level is possible, but unless you now what you are doing, I wouldn't recommend going there considering the voltages that will be present, even when switched off.

 

[Big_Spark]

Thanks Igorian..cleared that up..

 

[Steve]

When my PC was downstairs, the PC was on the other side of the wall to the microwave. When the microwave was on, the image would shake violently. Also had a subwoofer, when it was near the screen, the image developed a deep coloured patch on the corner where the sub was. All magnetic interference.

When my 17"CRT was on its way out, the cathodes were switching off intermittently, causing deeply colour biased images. Banging the monitor cured it temporarily

Dont know if any of this helps.

 

[ban-all-sheds]

Does it happen more often if the screen has a predominently white or light coloured background?

Or when it has a predominantly pink coloured foreground?

 

[Igorian]

Does it happen more often if the screen has a predominently white or light coloured background?

Or when it has a predominantly pink coloured foreground?

You bin at the paraffin again?

 

[ban-all-sheds]

No - just thinking of possible predominantly pink (or various shades of brown etc) images that might cause blurring and shaking of vision....

 

[CaptainKirk]

I wish I had not read this. As an electrical installation inspector I investigated numerous complaints about this with the old CRT monitors in the 1990s.

While other equipment can create external influences, the problems which I encountered were of the IT hardware nature and were solved without fail by changing the monitor "refresh rate".

Now the stupid bit, with more and more flat screens being used I have never come across this for years and I can't remember how you do it - I'll try and find something.

CaptainKirk

 

[Softus]

I wish I had not read this.

Well I wish I had not read what you've written, being as it's of almost no use to anyone.

Causes of the symptom as described, in order of frequency of occurrences (in my experience):

1. Data lead from monitor to video port not pushed in tightly.
2. Faulty Monitor.
3. If a desktop PC, graphics card CPU fan failure.
4. If a laptop, too much fluff in the heat sink.
5. If TFT, wrong power supply in use.

 

[JohnD]

I've only had it from mobile phone near the screen.

I wonder if its a TFT or a tube?

 

[Igorian]

Well I wish I had not read what you've written, being as it's of almost no use to anyone.

Now Now sweety. You're not in plumbing or electrics now.

 

[Softus]

Now Now sweety. You're not in plumbing or electrics now.

If this isn't an electrical problem then I'm joe-90.