I have a Sony Vaio VGN-NR... which has had the same problem as a lot of other VAIOs yet with mine it is a different case. The AC adapter works fine and when the cable is plugged in there are no LED lights on. When i turn the laptop on with the cable in the green power light comes on but that is it. No slight sound from the laptop at all, as though it isnt trying to start up. When i press the power button and hold it the battery light comes on and stays orange for as long as i hold the button. I have tried this procedure with and without the battery inserted. I have also tried the same thing without the charger but this time the battery light is a constant orange no matter what. I cant turn off the laptop without removing the battery (no matter how long the power button is held for). I have also tried leaving the battery out for a few days to let the power drain from the battery but still the same problem.
Overall, the fans dont attempt to start, there is always a black screen and LED lights come on as stated.
I obviously dont want to send it to Sony as they'll charge a lot for something i probably could have done so if anyone has any advice as to why my laptop has all of a sudden started doing this then i would be grateful.

There are many similar posts identical to yours and it amazes me that they are all Sony

It's possible your motherboard may have died. The only thing I can suggest is disconnecting the power cable, remove the battery and press the power button for 30 seconds.

Try powering again and see if anything comes on.

Hi, did you find any solution to this? I've got the exact same problem with a Vaio and your post is pretty much the only thing I can find on the Internet about the same problem.