My Dell D610 laptop monitor has went completely white.

Try connecting an external monitor to the 15 pin VGA (Video Graphics Adapter)and see if you still get a white display. You may have to hold down the function key next to the space bar and depress the key with a picture of a monitor on it to send the video signal to the monitor.
If you still get a white display on external monitor then you have a problem with the laptop's video card.
If the display on the external monitor is fine then you have a problem with the laptop's LCD display panel or I/O cable and they need to be replaced.

hello, Plug your laptop to an external monitor and restart,maybe it is a VGA problem,if it does not start change the RAM,if it does not start again,then there is a problem with the motherboard

Make sure you have not accidentally used the FN+F5 key
That combination sets the laptop to use an external display.

If using that does not give you a display take a small torch (flashlight if in USA) and shine it at an angle on the laptop screen.
If you can see any sort of picture you would be looking at replacement of some minor parts to the laptop screen

Hope this gives you the information you need. If not add any extra information you may have and lets see if we can FixYa

Bob
Moderator

It would be very decent of you to consider the quality of our expert’s answers and judge them accordingly as you pass through FixYa.

Thank you

If the system appears to POST, but displays no video, then try the following:

1. From and off power state, press D + Power and see if the LCD Diagnostic runs. You should get 4 solid color panels (RGB and white)
2. Try running the system with an external monitor (Fn+F8 to enable the VGA port)

If the LCD diag fails and you get video on an external monitor, then the LCD and or the LCD Backlight have failed. ($100 or so on EBay for a replacement)
If the LCD test comes up, and you can't get video in the BIOS or in the safe mode (No Dell Splash screen etc) on the LCD then most likely a motherboard, also about $100

Hold the Fn key and press the up arrow.

you are try to get sound for external sound. maybe you put the jack in wrong hole ? or your external device isnot working. or your volume is not high. 
try these pls. and notice us.

there is a inverter in LCd that makes your lcd bright white shine. when it breaks down you see black screen. something happens on lcd you cant see clearly  you should go to service and need to be changed INVERTER.
pls rate

Are you sure the laptop is powering up?
Do you hear the laptop boot up and the hard drive spinning and the power LED is on when you connected the external monitor?
The monitor must be powered up before the laptop for the video info to switch video port automatically.
If the external monitor is blank then you can't make it work, your video card is faulty and it is not possible to replace as it is built-in on the motherboard. You could replace the motherboard but this may not be a cost effective solution,

London the only option is to replace the display or the back light itself. If money is tight you then can use an external display but that does limit your mobility. I had a D610 go out on me but it would work if hooked up to an external monitor. Once I replaced the display it was fine.

Did you hold down the Fn key and press the function key for the external VGA port? It should cycle as LCD only, LCD and VGA, VGA only and then back to LCD.