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I have installed an external monitor (Dell ST2220L, 21.5 inch) on my laptop (Sony Vaio). I am using a DVI-D cable for connection. Since the laptop does not have a DVI-D port, I have connected a DVI-D to HDMI connector on the laptop end and inserted the cable in HDMI port of the laptop..

I have switched off the laptop display and adjusted the screen resolution on the Dell external monitor to 1920 x 1080 and adjusted colors for the Windows 7 and brightness and contrast from the monitor.

The problem is the monitor turns of blank intermittently for 1-2 seconds and turns on again at random interval. What could be the reason for this and how to get rid of this problem?

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up vote 0 down vote accepted

This seems to be a connectivity issue. Try and wiggle the adapter, and all the connections while powered, and see if you can make the problem appear. Don't forget to test the connection at the display too.

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I tried wiggling all the connectors but could not make the problem appear. – Gaurav Agarwal Oct 19 '12 at 15:18

I believe it's most likely a bug in the generic Windows display driver. It's possible you can solve this with a driver from Dell for your display.

I've struggled with exactly that same behavior in one of my monitors, where it randomly goes dark for a couple seconds, then comes back on. The interval between could hours or it could seconds (almost constant flickering.)

In my case, it's two Dell 2405FPW panels side-by-side on my desktop and the problem only presented on my left monitor. Web searches at the time confirmed this a common problem, but seen only on the then-new Windows release I was running and could be traced to Dell having dropped support and not releasing a driver. The random behavior was because I was using the default driver. It drove me nuts for years (but I was too cheap to buy new panels that were supported.) The problem finally (fingers crossed) appears to have gone away a couple months ago with an Nvidia update for my graphics card.

In your case, I don't see others reporting the same behavior with your model and it looks like Dell still supports your monitor. But the behavior you're seeing is exactly what I saw from the default driver. This is why I suspect it may be as simple as downloading the proper driver from Dell.

Good luck. I hope this helps.

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I believe it is an HDMI issue as I am having the same problem with a new Vizio 50-inch LED TV. When using HDMI to watch cable tv or Blu-ray discs I get intermittent "no signal" displays where both video and audio disappear for a couple of seconds and then come back. Using component connections I don't have that problem. I don't like using component since the picture quality is not as good, but I can't find a better solution for the time being.

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