My SONY laptop VGN-BX61MN boots ok but very faint background running with black screen. I have plugged external monitor and rebooted the system but say thing happening. Anyone there with solution pls?

Sounds like the screen is going bad. Isolate the problem by plugging an external monitor to the laptop. Borrow a monitor from a neighbor, friend, relative or co-worker to plug to the laptop. It can be any kind of monitor even the old big fat crt monitors as long as it has a vga cable to connect to your computer's vga port. If the Borrowed monitor does not show the black lines and snowy background, that proves your video card is ok and the problem is your lcd screen. If the borrowed monitor shows the same black lines ans snowy background it means your video card inside the computer has the issue.

The video will show on most systems when you reboot without you having to do anything. Some systems will require you to hit the FN (Function key) + F1 thru F12. Hold down the FN key then hit the correct key for displaying on the monitor (F1 thru F12). The correct key will normally have CRT/LCD on it or it will have the icon of a display.

Does it seem like it booted up all the way except the screen is black? If so try the steps below.

Shine a flashlight on the dark screen to see if you barelysee the icons on the desktop. If so, then the LCD Inverter is bad.

Plug in an external monitor and see if the display shows up on it. It can beany kind of monitor even the old big fat crt monitors as long as it has a vgacable to connect to your computer's vga port. If so that proves yourvideo card is ok. The video will show on most systems when you rebootwithout you having to do anything. Some systems will require you to hit the FN(Function key) + F1 thru F12. Hold down the FN key then hit the correctkey for displaying on the monitor (F1 thru F12). The correct key willnormally have CRT/LCD on it or it will have the icon of a display.

If you see no icons by shinning a flash light and the external monitor works,then your screen is bad. If you see no icons by shinning the flash lightand nothing shows on the external monitor, then most likely your video card isbad.

could be invertor board or back light

Shine a flashlight on the dark screen to see if you barelysee the icons on the desktop. If so, then the LCD Inverter is bad.

Plug in an external monitor and see if the display shows up on it. It can beany kind of monitor even the old big fat crt monitors as long as it has a vgacable to connect to your computer's vga port. If so that proves yourvideo card is ok. The video will show on most systems when you rebootwithout you having to do anything. Some systems will require you to hit the FN(Function key) + F1 thru F12. Hold down the FN key then hit the correctkey for displaying on the monitor (F1 thru F12). The correct key willnormally have CRT/LCD on it or it will have the icon of a display.

If you see no icons by shinning a flash light and the external monitor works,then your screen is bad. If you see no icons by shinning the flash lightand nothing shows on the external monitor, then most likely your video card isbad.

Yes it's repairable.

Shine a flashlight on the dark screen to see if you barelysee the icons on the desktop. If so, then the LCD Inverter is bad.

Plug in an external monitor and see if the display shows up on it. It can beany kind of monitor even the old big fat crt monitors as long as it has a vgacable to connect to your computer's vga port. If so that proves yourvideo card is ok. The video will show on most systems when you rebootwithout you having to do anything. Some systems will require you to hit the FN(Function key) + F1 thru F12. Hold down the FN key then hit the correctkey for displaying on the monitor (F1 thru F12). The correct key willnormally have CRT/LCD on it or it will have the icon of a display.

If you see no icons by shinning a flash light and the external monitor works,then your screen is bad. If you see no icons by shinning the flash lightand nothing shows on the external monitor, then most likely your video card isbad.

If you shine a flashlight on your black screen and look real hard for the icons on the desktop. If you can faintly see them that means your LCD Inverter is bad. You'll have to disassemble the LCD Screen to get to it. In the mean time you can attach another monitor (LCD Flat Screen or the Old style fat CRT) with a VGA cable to the vga port on you laptop. Once you have it connected hit the FN (Function Key) + (F1 thru F12) key that that corresponds to the external display. Hold the FN Key while you hit the Function Key that is for the external display. The key might have the words LCD/CRT on it or it might show a display symbol. That's the key you want to hit while holding down the FN key. This will cause the desktop to display on the external monitor and verify that there is no problem with your Video Card inside the laptop.

Ok ! So try one thing remove HDD from the laptop and then start the laptop.And i am sure that u will see that the screen gone black at certain points. So dude its LCD problem . Go to nearest Laptop repairing center and he can change your LCD. then it working properly

sounds like the backlite for your monitor needs to be replaced. (like the lightbulb went bad) These can be replaced usually, for under 100 dollars.

To determine if the LCD is faulty or the video card, connect an external monitor to the video port on the laptop, power up the external monitor first then the laptop. The video data will divert to the external monitor automatically and if you get a normal Windows image the the video card is OK and the fault is the LCD screen or video cable.

First, try booting into system setup. That will require hitting F1, F2, F8, f10, esc or del when bootup starts. It varies by computer and you didn't identify yours. If setup is also dim, your backlight is bad and needs to be replaced.
You could still use the laptop with an external monitor but that is not a very portable option.