Blank screen Dell Inspiron

Hello all;

My Dell inspiron laptop was perfectly working for the past 2 years, though with minor issues in between. However I restarted my laptop in the morning which said "update and restart". Since then the system isn't starting. Here are a few points if you can help:

1. Earlier issues were the system heats up very fast.

2. System auto shuts while playing a few games.

3. Now after the restart (with update) that I did today morning, windows doesn't seem to load. I can see the Dell logo at the start up. After a few seconds the system goes black (with backlit display). However it doesnt show the windows start up or welcome screen at all.

4. I still see the LEDs of power glowing; backlit display on the keypad glowing when I move the mouse. It hibernates as usual after sometime. However I donot see anything on the screen except for the dell start up logo.

5. The system is Dell inspiron 7520, Win 8.1, 8 GB RAM. I did try removing the battery, discharging the static electricity unplugging the adapter. But it didnt help me.

6. I am unable to get the safe mode way by using F8 key. Is the procedure different for 8.1 windows? Can you please suggest?

Can the tech experts please help me? I really need tour help please. I have a lot of data in my 1TB hard drive.