I have a Lenovo thinkpad and one day it just wouldnt turn on properly, it would just freeze on the red Lenovo logo and be stuck there. What worked for me was
Pressing the power button on for a few seconds for a hard stop
Then pressing it back on, and immediatly press enter to load the boot options
Press f12 to select @coose a temporary startup device@
Select ATA HDDO SanDisk, press enter
And it worked, it went onto the windows logo screen and the laptop turned on as normal.[br]
I backed up all my files just in case after I managed to turn it back on.
Hope this helps