I have a Dell Inspiron 15r 5537 (6GBRAM,2GBGRPHIC,1TBHDD). (WIN7)
Everything worked fine.. But from few days ago my screen blinks (Vertical lines Blinks(SOMETIME not all the time))during BOOT and Starting windows.. and returns back to normal and this also happens when resuming windows too.. But it gets all set when it asks for password.. All drivers and BIOS is up to date..
The thing whch gets my attention was.. When i press my power key it starts to blink rather than showing the dell icon and press f2 for Setup.....
I also reinstalled my OS.. But no use..
I also ran Diag. it shows all test passed...