Windows 7 - my laptop not working only black screen

hello i have asus laptop before 2 dayes when laptop was working properly .then i put it on stand by for aperiod of time abut an hour so when i returned i turned it on it but it operated with ablank screen i tried many times without any result i dissemble ther battery and turned it on directly from electric charger and nothing changed i connected it to aplasma so nothing happened when i turned it on lamps is blinking normally but no screen shown

Hello! Does it show the ASUS logo when turned on or it stays blank the whole time? Have you tried removing the RAM memory and placing it back? Does your laptop have a dedicated video card (not onboard) ? First of all, what is the model name? When you connect it to the plasma do you press the Fn + F5 (i think it is F5) or the key that has the symbol of a monitor on it?

no nothing displayed when i turned laptop on
niether logo niether boot screen

So here is what i would do:
1. remove memory from it (if it is easily accesible) and if there are 2 modules try one at a time so to see which one is bad
2. if bios battery is visible remove it then short circuit the battery conector for a few seconds. For this you must remove the main battery and power supply !
2. remove video card (if it is separate video card) clean contacts that go in the slot with contact cleaner spray then put it back in
3. if there is no separate video card i would reheat the video chip on the motherboard or northbridge if there is no separate video chip. If you have electronics skills, if not go to a computer service ask them to do it. That will give about 1 year of life to the laptop but no more, then you will need motherboard

I would say you should take your screen completely off video card and all then put it all back on if that does not work then you should take every thing in your laptop out and clean all connections completely dis assemble your laptop remember to take that little coin cell battery out then leave it like that for 30 minutes then once it's been 30 minutes put it all back together if that does not work well i'm out of ideas.