Dell Inspiron 3537 won't boot normally

Hi to all,
I have a strange problem with my Dell Inspiron 3537.
One day I shut it down via start>shut down,and after a few minutes I needed to turn it on again and when I pressed the power button it turned on,showed a black screen and shut it down on its own.I pressed the power button again,this time it showed black screen again but didn't turn off,I could hear the fans working and only the power light on(the hdd light was off).
I turned it off,and pressed the power button for 10-15 times,the problem repeated but one time it somehow managed to show the Dell splash screen and booted normally.I firstly thought that the problem is caused by a virus,so I formatted the hdd and reinstalled the win7 ultimate 64 bit.The laptop worked for a few hours without any problem,so I decided to shut it down again via start>shut down,and when I wanted to check if it will work without problem,and when I pressed the power button the same problem again!!
After a 10-15 tries I somehow managed to boot it again and this time it showed a BSOD:error stop 0x0000001E
After this Finally I did a startup repair with the Win 7 installation dvd and the repair showed me this : The following startup option will be repaired name: Windows boot manager and etc. and :The following startup options will be added:Windows recovery enviroment etc. After that repair I decided to shut down the laptop via the same way:start>shut down, and when I tried to start it the same problem!Black screen with only power light on and sound of working fans or shutting down for a several times.
After that I ran the Dell board diagnostics and all of the available hardware tests from the Dell support site and all of the hardware components passed all of that tests succesfully.
I found a way to boot it after pressing and holding the power button for more than 3 minutes,with the AC adapter disconnected and the battery removed,then reconnecting the adapter and putting the battery back.
But now I can't boot it every time successfully even using that way I found.

So,I need help!
Is there a way I can fix the booting problem on my own at home?
I don't want to give it to a service for repair!
But I wan't to fix it without opening it!
Is there a possibility that the problem is caused by dust accummulated inside the laptop or there is a problem with static electricity?
Anyway PLEASE HELP ME!I really do need this laptop for studying!
I will only repeat that all of the hardware tests didn't show a problem with the hardware!
Any help would be appreciated!
THANKS IN ADVANCE!!!!
Best regards!