Inspiron 17R 5737 wont go to sleep!!

so i bought this laptop yesterday , And immediately i saw a big problem , there is this sleep issue in this laptop , and like all other customers , When I close the lid on my system for more than a few seconds, it takes about 30 seconds to re-start, and I lose all of my open Web sites, documents, etc , i mean its like shot down!!

and I have tried many solutions , and i had to read many topic about this problem , but nothing works!!

i have installed all the updates , the bios , the graphic card , also i make a refresh 

but nothing work!!

please help me to solve this problem!

thanks