Rank: Guest 
|
Posted By Darren Honeyford
Can anyone help, I have have been asked a question about the installation of new PC's, the screen's of these PC's keep having multiple flickers in this certain area, all the eletric's have been tested which are fine and other PC's currently in use elsewhere have been sited in this area with the same results as the new PC's.
I have heard of eletomagnetic fields before but nothing in depth, any help would be much appreciated.
Many Thanks Darren
|
|
|
|
|
|
Rank: Guest
|
Posted By Jim Evans
Darren,
just an idea, have you checked for mobile phones in the area? Even when not in use but switched on they can interfere with the screens of computers.
Jim
|
|
|
|
|
|
Rank: Guest
|
Posted By Robert K Lewis
Darren
This problem only tends to occur where there are higher voltage cables than 240 volts. It is essentially the resultant mag. field induced by the current flow in the cables. This produces both distortion and/or flicker. Most competent electrical contractors can measure this field and design the appropriate screening around the cable.
The other possibility is some piece of equipment that is within this area that is either producing changes in the local circuit or perhaps more rarely a magnetic field as a resultof its operation. It does need attention though if you intend to leave the PCs in the area as it is bad for the eyesight and can I believe induce underlying illnesses to respond eg Migraine headaches
Bob
|
|
|
|
|
|
Rank: Guest
|
Posted By Bryn Maidment
Darren
Don't know if it's the same thing but if I switch on certain pieces of equipment within 3-4 feet of the monitor, it flickers badly. These items are my fan heater under the desk and a desktop fan.
There is obviously some form of EM incompatibility but it may be worth checking that adjacent equipment isn't at fault
|
|
|
|
|
|
Rank: Guest
|
Posted By John Donaldson
Have a look at whats on the other side of the wall, so to speak.
If there is a switch room, plant room etc its possible that this could be causing the effect you mention.
Even a small magnetic field is likely to cause problems. If the effect is transient it could be related to an item of equipment switching on and off. A boiler for example.
|
|
|
|
|
|
Rank: Guest
|
Posted By Jim Walker
Although the other responses are correct and worth checking, here is another dimension:
All equipment sold in the EEC must have EMC immunity i.e things described in previous replies should not effect the VDU.
Have you aquired some "cheap" equipment? False CE marking on computing equipment is rife.
Get the supplier in to sort it out. Threaten him with the EMC directive.If they don't react, see the local trading standards people.
|
|
|
|
|
|
Rank: Guest
|
Posted By Bill Fisher
Jim
Whilst I understand the point you make the previous responses are all relevant and possible. My company buys its equipment from a national company (Dell) and I have experienced Mobile Phone interferance, magnetic interference from (eg) speakers too close etc. I am also aware of others who have been affected by the "room next door" scenarion.
So whilst your reference to EEC and EMC is relevant, it does happen.
Regards
Bill
|
|
|
|
|
|
Rank: Guest
|
Posted By Bryn Maidment
Agree with Bill! My new Dell has just been 'flickered' by my new fan heater(reputable make, with CE mark)at a distance of 4 feet. Now to try my mobile phone......OK! so its a quiet morning I have time for these important things!
|
|
|
|
|
|
Rank: Guest
|
Posted By Ashley Williams
Just an additional couple of suggestions: -
Is this area under communications equipment e.g. Microwave transmitter or Mobile communications mast.
You could even look at the buildings around you. One of my old civil service sites was opposit a police station and had similar problems.
Have you tried altering the refresh frequency of the graphics cards from the the optimal setting?
hope this might help
Ashley
|
|
|
|
|
|
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.