Samsung monitor dims then brightens then dims

  awest3 16:32 17 Feb 2015

Hi, I cant find out what's causing my monitor to dim/brighten/dim constantly. Its Windows 7 Pro with no dimming options. I've changed the power option to 'High Performance'. Changed the cable, Changed the cable for HDMI, added a video card in place of the onboard graphics, checked for electrical interference, checked for magnetic interference, shielded the monitor with silver foil, checked the power output on the monitor feed and changed the monitor for a spare I had (thus ruling out the monitor as an issue. I've checked just about every setting for display there is, I think and still have the issue.

Any ideas gratefully received as ever.


  Fruit Bat /\0/\ 18:51 17 Feb 2015

Changed power cable? check wiring in sockets not loose?

checked voltage at socket is not dropping with a load coming on off your house power circuits

  • had something similar when neutral connection on fuse box had partially burnt away - weird electrical happenings when shower or tumble dryer were on, luckily found it before house burnt down. :0)
  awest3 18:24 25 Feb 2015

Thanks for this, sorry for the delay in replying..been a bit ill.

I tried moving the electricity supply to another socket but it made no difference. I then left all the connections in place and connected a different PC.. no dimming at all...! this used all the cables, monitor and connections in place for the dimming PC.

It maybe that the power supply is not up to the job ...? not sure what is in the machine..I'll find out.

I've used SIW to look at the machine and it says that dimming will occur after 300 secs, although the machine zoostorm i5 4750, 64bit, 3.2ghz 8 gig of ram, with w7 home premium does not seem to have any adjustment controls. As it happens whilst using the machine I'm discounting this..

I'll get back when I've discovered what size PS it has in it..

Thanks Al

  awest3 15:06 24 Mar 2015

I tried a new power supply in the PC, no joy. I ran a power cable from another room but the issue remains. I tested the output of the adapter which at 19 volts is what it says on the package. I moved the screen away from the desk and it was still the same. So no nearer a solution on this one. Maybe its just a faulty monitor....

  awest3 12:35 15 Aug 2015

just thought I'd update this. The monitor it turns out had a 24 month guarantee (18 months in). Its been back for repair now 3 times.. First time it came back it would not power on, second time it worked but the original fault was also there. Its due back on Monday so we shall see. They've said if they can't fix it in 3 tries they will replace it.. I'll let you know.

  bumpkin 14:36 15 Aug 2015

The fact that it worked with another PC confuses me a bit otherwise I would say a failing capacitor in the monitor. Been back for repair 3 time already does not inspire much confidence anyway, lucky it is still under warranty.

  bumpkin 14:45 15 Aug 2015

Hold on a minute.

* changed the monitor for a spare I had (thus ruling out the monitor as an issue. *

  bumpkin 14:47 15 Aug 2015

Does that mean that the other monitor was doing the same thing.

  awest3 15:43 15 Aug 2015

Sorry I did not put that as well as I should have (I noticed it myself when I came to do the update - I seemed to be contradicting myself, its probably old age) . What I meant to say was that I swapped out the monitor for another and it did not have the same issue. I then tried the faulty monitor on a different PC I have and the blinking started up again after a couple of minutes.

  awest3 10:57 17 Aug 2015

Hi, The monitor has arrived back with a new screen. All seems well so far I'll leave it on for a few hours to test it but it all seems ok at the moment. I'll get back to you if I have another problem. I find its had a new circuit board, power supply and now a screen. I think it would have been cheaper for them just to replace it.

Last thing is (another senior moment) it's an LG not a Samsung. I have to say that their customers services have been brilliant throughout the issues. fingers crossed..Al

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

Dell XPS 13 9370 (2018) review

HomePod review

Comment regarder les Oscars 2018 ?