Flickering screens

[reprised]

Hi,

 

I have a strange issue with our two display screens in reception in that they keep flickering. I have tried different cables and different PCs however the flickering doesn't go away. I noticed that the flickering stopped on both when I used a laptop on battery but as soon as I plugged it in the flicking began again. What the hell is going on here?? Anyone have any ideas how I can solve this problem as it is so annoying.

 

Thanks

[elsiegee40]

I'm thinking interference. Have you tried moving the screens to another room and seeing if they still flicker? Edited January 17, 2011 by elsiegee40

[witch]

See this thread for more info on interference: http://www.edugeek.net/forums/how-do-you-do/68275-audio-feedback.html

[tech_guy]

I had this with a PC connected to a screen at pos. The moment the power supply in the PC was swapped out the flickering disappeared.

[rad]

its as if it is a power issue, as said, swap monitors for another and test in your office. Its more likely a nearby power pack or plug is the issue.

[plexer]

Ground loop.

 

Ben

[witch]

Ground loop.

 

Ben

 

As I said, in the thread 'audio feedback' the problem was an annoying hum but interference from the mains is interference from the mains no matter what the result! I dont know if the hum eliminator would work but if it smoothes the signal then it should eliminate the flickering, shouldnt it?

[reprised]

Hi Guys,

 

Thanks for the replies. Unfortunately I can't move the large display screens as they are both mounted on the wall. No matter which PC or laptop I use I get the flickering unless I run the laptop on battery. I have tried plugging the power cable into different sockets and turning off as many electrical appliances as possible however to no avail. I had a look at the interference thread and was wondering if there is something that can filter the interference like the hum eliminator? Would a ferrite core work??

[mattx]

Blink faster.

[Chris_Cook]

What sort of power cable does the monitor use? Try replacing it. If it uses a figure of 8 connector, then try plugging the small end in the other way round. If there is an external power supply on the monitor, try changing it for another.

 

Also, are the monitor and computer plugged into the same socket?

[plexer]

If you have one available try a ups on the laptop power supply.

 

Ben

[zararh]

Hi

 

I have the same problem.

 

We have a Large Plasma down in the hall. Upstairs in reception we have a 1 computer feeding the reception dispaly and the Plasma down stairs. Via an Video amplifier in reception and a Video amplifier down near the Plasma. We also have a TV feed from the 3rd floor to the hall. When we switch to TV it does not flicker BUT when we use a power point it flickers.

 

If we use 1 output from the PC to show the powerpoint in the hall and NOT the reception the flicker stops!

[DarrenC]

These sound like dirty power issues.

 

You could try a supressor or power filter but there may not be a lot you can do about it. In one school I dealt with the screens would flicker when the corridoor lights came on and in the staff room when the fridge compressor kicked in the screen turned off!

 

I would have a chat with your electricians and see if they can suggest some way to clean up the power supply.

[LukeC]

You could try using a different plug on a different ring main see if this makes a difference

[reprised]

I have found a solution to the problem :-). I dug out a laptop which doesn't come with an earthed power lead ie 2 pin ac adapter, connected it up and the flickering has gone. Thanks for all of your suggestions and help.

[Marc-Engineer]

You have, as mentioned above an Earth loop where you have 2 earths to the same device, that will often cause interferance, Usually audio noise but can be Image problems you often can fix it with an earth break in the lead to the audio or video but you seem like you have sorted it by removing your second earth.

 

Marc

Projector Engineer