Why is computer screen black after switching the power on?

I was using chrome, charge was 20 %. Then, screen got hanged and totally black in a few seconds. I tried switching it on again using the power button but realized it was already on and the screen was displaying anything. I charged the laptop for a few hous and tried switching it on again but to no avail. There was no BIOS update or windows update. I was simply checking my mails and doing some code when this happened. Its been 3 days and the screen is still black after pressing the power button. I have already tried going into recovery mode for troubleshooting using Alt+F10 keys but to no avail. Nothing is displayed on my screen but the battery still runs out. I am now charging it again as the light started blinking after I pressed the power button which indicates that the charging is low. The customer support 1800-11-6677 is not available since two days and chat support is also not available. Kindly help me out.