Sony VGN-A790, 17? 1920x1200, ATI 600x (256MB) screen went dark when I connected a digital external monitor, worked fine with an analog. Any external monitor works. primary is so dark it looks blank unless you look at an angle. Occasionally it blinks with normal contrast then goes dark again. ati had a brief web note stating connecting a digital monitor & screen going blank was a known problem without solution. tried everything except reformatting the hard drive. could this be mechanical or voltage problem? Changing graphic cards? I hate to toss a 1920x1200 17?

Hi there

regarding that issue that you are having with the external monitor is not working with your sony vaio here are some steps that might help to have it working

connection between the monitor and laptop
- VGA ( blue adapter ) or DVI ( white adapter )
- check if the connected properly
- try to use a different VGA cable
- check if the monitor is detected by the computer
***please also do a monitor selftest on the external monitor***

- HDMI
- check if the tv is detected by the computer
- check the settings of the TV for the HDMI

hope this helps

Could be a bad backlight lamp or a bad inverter board. Please refer to the following article for more details on how to diagnose & fix this problem:
http://www.fixya.com/support/r6430776-troubleshooting_laptop_power_failures

Have you tested it with an external monitor?

I would say you either have a damaged inverter board or screen baclight lamp. Usually the inverter board fails in one of the following ways:

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

if you want to use it on an external monitor just download and install the latest drivers for your video card with the monitor plugged in the problem with you lcd is probably the ccfl went bad they are mini flourecent lights inside the lcd you need to dismantle the lcd then remove the old ccfl and solder in the new ones here is a link that sould help with the installation http://www.lcdparts.net/howto/troubleshooting/LaptopCCFL1.aspx

if it has a plug for bga ...than it will work with an external monitor...most laptops are working just fine with external monitor..

Did you accidentally push the Function + (whatever) keys that switch the video out to an external monitor screen?

If the backlight of the LCD screen went bad - you could turn off all the lights - need a very dark room - you could still see the contents of the screen.

I notice a difference in the setup of the two monitors, have you installed the correct driver for the new screen?

Try F8 on startup to get into safe mode, this should allow you to use the default VGA screen, and to reset the correct monitor drivers.

This is because your screen is not compatible with any resoultion past 1280 x 1024. Look at your screen's specifications here: http://downloadcenter.samsung.com/content/UM/200602/20060210090838125_BN59-00521A-01Eng.pdf (Page 76 listed as Maximum resolution)

If you want to go past that, you must purchase and/or use a different monitor. Just be sure to look at the Maximum Resolutions BEFORE you purchase a new monitor!

uninstall ALL video drivers reboot computer should reboot with standard windows video drivers does the screen still play up if so you may have faulty video card.let me know please

Try connecting an external monitor - if you get a picture then the laptop screen may be faulty or turned off.