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Hello sir can you please tell me the full model number of the laptop which you can find on the bottom of the laptop.The full model number looks like C655-S5047

OK thanks one moment please

when you turn on the laptop can you see the Toshiba start-up screen

when you press the caps lock key does the light for the caps lock shows up

OK please try the following
Press and hold the power button for 2 or 3 seconds to shut it down and then disconnect the AC adapter. Remove the battery and press and hold the power button for about 60 seconds. Releases the button do not insert the battery back now plug the adapter back and turn on the computer. See if the problem persists.

Restart the computer then press F8 repeatedly. then you will get Advance boot Menu on the Advanced Boot Options screen, use the arrow keys to highlight the Safe Mode and then press ENTER.

see if you can access advance boot menu or safe mode

can you connect this laptop to a external monitor or TV using a VGA cable or HDMI cable and see if you can get the display on the external monitor

ok then can you find the memory module bay on the bottom of the laptop

Sir please try the following
turned off the laptop then Press and hold the 0 (zero) key on your keyboard while
powering on the computer.

ok then one moment i will give you picture of the memory module location

please check this image

Full Size Image

can you identify it

in the image the cover if the memory module is opened

you mean screw driver

ok

ok does the hard drive light blinks when you press a key

OH OK so the screen display have a very low brightness am i correcgt

i mean correct

but you can hear the windows start-up sound am i correct

ok press and hold the FN key and then press repeatedly F7 key and see if the screen shows anything

press and hold FN key and then press F5 key once and see if the display shows up if not again press F5 key

ok it seems like either the laptop screen power inverter board or the back light of the screen is not funtioning

you can confirm that by connecting the laptop to a external monitor using VGA or HDMI cable if that works then its a screen issues as i mentioned above

Is this laptop still under warranty

Also if the External monitor also doesn't work then its the display chip on the motherboard which is not functioning

it most probably a screen issue

because you can hear the windows start-up sound

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