Laptop-skärmen släcks

Har den en mekanisk eller magnetisk brytare för att känna om locket är nere?

I bland kan trasiga magnetiskabrytare ge liknande problem som du har.

Saxat ifrån majorgeeks.com

If your laptop starts up but you panel is blank (or goes blank) then get a flash light and see if you can make out anything on the screen.

If you can see the boot process and desktop icons, then the problem lies with the following:
1. The LCD panel's backlight (which is incorporated into the top of the lcd)
2. The inverter, which provides the power to the LCD
3. The LCD lid switch. This can be a mechanical switch ie lever or magnetic ie a small magnet on the inside of the screen bezel and a magnetic switch adjacent on the laptop base usually on the power board.

Check the LCD lid switch first if you have a problem as this switch controls the power to the inverter. If the inverter fails to operate then the lcd backlight will not come on.

In my case the Dell Inspiron 2650 has a magnetic switch. After having replaced the panel and inverter, the problem continued. I eventually discovered reference to the switch. I guess the magnetic switch on my laptop must be faulty in some way preventing the inverter from providing power to the LCD's backlight. Hence why windows boots but the LCD panel remained blank for a few minutes and then comes on or visa versa.

To test the magnetic switch remove the bezel (around the LCD panel) and the plastics over the power board to reveal the magnetic switch. Then place/move the magnet in the bezel over the magnetic switch and you will see the LCD panel turn on and off. With my laptop this happened but was eratic in terms of its operation and hence there is a strong presumption that the magnetic switch is at fault.

I purchased a new power board (which incorperates the magnetic switch for the LCD panel) and the panel(s) (both old & new) now works faultlessly.

As a postscript, if xp>power options is set to 'sleep' when panel is closed then the problem will be further compounded since as soon as windows detects the closed panel (due to the faulty lid switch) it will 'hibernate' and the pc will shutdown. So the symptoms would be blank screen eventually followed by shutdown (which is the tough problem I had).

Ett sätt att se om du har magnetiskbrytare är att föra något metalliskt över överkanten på skärmen för att känna om det finns någon magnet. Magneten kan ju sitta någon annanstans dock.

Exempel: http://www.youtube.com/watch?v=PBHJ4qkNpnA