Hi! My Viewsonic VA721 LCD Color Monitor's screen is getting darker over time. I've had it for about 5 years. Is it just getting "old" and worn out or is there something I can do to correct the problem? Thanks, in advance, for your help. Vicki T.

1) To unlock the monitor: http://www.fixya.com/support/r4554177-viewsonic_monitor_lock_unlock

2) I am not sure about the red light, are you taking about the power light or you are getting red tinting cast on the screen.

3) The monitor is old will more likely to have problem in the power supply by now due to bad caps and it can make the monitor act strangely. I am not sure what you mena by loos power cable.
http://s807.photobucket.com/albums/yy352/budm/Viewsonic%20VA721/

I would not suggest you to try to take it apart since there are high voltages inside that can kill you.

You need to set your PC video resolution to this monitor native resolution: 1280 x 1024 @ 60Hz.
http://www.viewsonic.com.au/support/manuals/files/LCD/Series%20A/VA721-1%20User%20Guide%20English.pdf

http://s807.photobucket.com/home/budm/allalbums

Please see here for what failed (bad caps) in this model: http://s807.photobucket.com/albums/yy352/budm/Viewsonic%20VA721/
Post back what you find so we guide you further.

May I ask what you mean by the windows does not recognized the monitor? You are not getting picture or you cannot set the correct native resolution (that is the best setting for best picture and aspect ratio)?
Native resolution for this monitor is 1280 x 1024 @60Hz.
And here is the common problem with VA721: http://s807.photobucket.com/albums/yy352/budm/Viewsonic%20VA721/

Yes here is a link to the drivers for your monitor> http://driverscollection.com/?H=VA721&By=ViewSonic
Thank you for using Fixya.com

ViewSonic VA721 VA721 Monitor Driver ... Login. Register ... Uninstall Windows drivers How to Uninstall Windows Drivers and why you need to know it ...www.nodevice.com/driver/VX500/get36507.html

Sounds like its going to sllep too soon make sure you do not have it set in your video card settings. also try it on a diffrent computer. if that does not shore it up replace the acpi board

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edwy_1a56970cf1ea4620

Check the cable who comes from the CPU maybe are damaged

http://www.eserviceinfo.com/downloadsm/6598/jean_ve710s-2.html

Go to bottom of the page to download the PDF . It has complete instruction and pictures

this is only an educated guess based on my years of computer and electrinics experiance. I believe the problem is the AC inverter that supplies current to the monitors back light,it powers up and fails. the monitor is working but without the back light you get a blank screen.The problem is fixable, but the delema is that for a technician to troubleshoot and repair the problem may cost as much as replacing the monitor since the prices have dropped so much in the last few years.