Recently thin horizontal bands (grey in color) have appeared on my screen. When I'm in Internet Explorer, these bands coincide with the text displayed on the screen (even when i am typing this question). Also, the 'Back' button which is green appears nearly fluorescently green instead of the usual green.

If this problem appears, You can try replacing the monitor data cable. It probably won't amount to anything useful, but it could be the cable. If it isn't, I'd say just get a new monitor because it is definitely a manufacturer hardware problem. Definitely try to test a different monitor out before you buy a new one, because if the other monitor is fine then you've singled out the problem.

The monitor only will run on default mode and it won't let me adjust resolution, and can't play games and can't even download sbc virus protections. I would suggest that you re-install the video driver, or download the most current from dell.com. I am assuming that you are using windows and know how to adjust your desktop settings. If you do not, then right click on your desktop, and select propertys, and then settings. You will then be able to select a higher resolution. If you can not, then, Select advanced, and then the monitor tab.

Verify that the monitor is listed correctly, if not go to the HP website, and look for the correct driver for the monitor, and download and install it. This should open up your choices for resolutions, color depths and refresh rates.

When I first boot the computer the monitor works fine, however, after a short time it goes blank (flickers then goes blank-gray). If I give it a whack or two on the top with the palm of my hand the display reappears and stays on without any further interruption. Is there something loose or stuck closed inside the monitor?

Please don't do anything to your display anymore, you can cause more damage. The issue is that a solder joint has failed on the pc board within the display. Most repair centers, TV or Computer, can repair this type of issue fairly cheaply. I would recommend doing this as soon as you can, since the intermittant failure can cause other issues.

My pc system is 18 months old and has been running perfectly on Windows XP. The last 4 days the monitor has switched itself off and on repeatedly when the system is booted up. The on/off button on the monitor doesn't function; it just lights for 1 second, then the screen flicks on for 1/10 second then it switches off, light on switch included, for another second. It will do this for hours. Nothing seems to help; rebooting (difficult if you can't see the screen), disconnecting power to the monitor. Then, suddenly, the screen appears and the monitor functions perfectly.

Is this a monitor or cpu/system issue? The pc has full service cover but the company who would repair the cpu say its a monitor issue and pass me to the monitor company while the monitor company say its a cpu issue and will not exchange the monitor.

If I understand your description correctly, the monitor will restore its self if you unplug it. That being the case I would suspect that the driver for your video card is suspect. I would try downloading the latest drivers for the mother board, video card, and monitor. If this fails then either the Monitor has its lowest resolution decoder chip failing or the video card is failing. The reason the monitor is flicking off and on is that it is not sure that it is getting a vertical and horizontal signal from the PC. It then goes into shut down.

The only reason this may be an errant diagnosys, is that the led on the front of the monitor, "Light", turns off as well. If it is turning amber or yellow, then this is the correct diagnosys, and the video card is likely the cause. Also be sure that the data cable from the monitor to the PC is fastened tightly to both connectors if you have connectors at both ends, if not at the PC.