Monitor flahes on then off

Jon12345 · 30 Dec 2010 at 12:48

I have two LG monitors on a dual monitor setup. Recently, the left monitor will not go back on if I turn it off. It flashes what should be seen (desktop) very briefly, for perhaps 1/2 second but then goes off again. So, I changed the monitor and the same thing happens with another LG monitor. The right hand side monitor always works.

So, it looks like the monitor is not so much the issue since even a new monitor doesn't make any difference. Oh, if I turn the monitor off for about 5 hours, sometimes it will turn on ok. Very weird.

Any idea what the issue might be? Failing graphics card or something?

Thanks,

Jon

razorback09 · 30 Dec 2010 at 20:19

mm maybe a fault connection on the graphics card?

Emphacy · 31 Dec 2010 at 01:50

my old PC use to do the same thing!
I think it's just that, the monitor doesn't recognize the low voltage coming from the graphics cards port, which isn't enough to fully wake it up.

I don't think it's a graphics card problem, I know loads of PC's I've came across that do the same thing.

When you first switch a PC on, it sends a much larger signal to the monitor to wake them up, then once already active, the signal is significantly reduced, which would explain why it doesn't wake up when turned off.

Jon12345 · 9 Jan 2011 at 14:05

Ok, so I have replaced my graphics card and tried a new monitor. Same problem. Occasionally, the monitor will work fine and stay on until the PC is switched off, but that is probably like 1 in 50 times.

When I turn the PC on, the POST screen used to show on both monitors. Now, it shows on the right one and shows for a fraction of a second on the left one. So its not a windows thing.

What I don't get is that sometimes it stays on for ever.

Could it be my motherboard or PC power supply?