laptop wont boot

Hello dear Readers, My laptop has an issue Everytime i wanna boot it up it just stays dead the cd starts spinning for 2 sec and stops then all LEDs turn on but i still have blackscreen and no fan is spinning Sometimes randomly after 7h or 2 days it will boot normal when its in the" LED on...

Hi, So i bought a new HP Pavilion 15 Gaming Laptop from a Laptop Vendor.I asked him to install a 256gb SSD onto my laptop.After the installation was done when i booted up my laptop it was stuck in UEFI Interactive Shell or sometimes it would say BOOT DEVICE NOT FOUND.I returned my laptop and...