It just happen I turn the Toshiba harman/kardon laptop PC on and after a minute I find out the monitor is not displaying. I have connect an external monitor to the left side VGA port but nothing displayed. The power, battery and PC on lights and orther are on even the cooling fan, but no PC bizz light and I cant hear any sound.

Irimakere, October 2013

Turn it off for about an hour, then turn it back on.
Does it power up and is the display on?

Does it turn off after some time? With the fan making more noise than they should do?

If it power on normaly but turn off by itself after some time, it may be overheating and get turned off as a way to prevent damage.

Make sure that the air vents are free of any obstruction.
Open the case.
Check the CPU heat sink. Make sure that it's free of any dust accumulation.
Also, make sure that the air duckts are free of any debrit and other obstruction.

Electro, October 2013