PN E1M82AV
Model 14t-K100
This is my son's month-old ENVY Ultrabook (touchscreen).
As of last night, upon start-up, following the HP logo screen, there is nothing -- save for a "strobing" bar across bottom of screen, on the far left of which is the Windows logo, on the far right a keyboard icon. Nothing is clickable, and touching the screen only makes it go black for a moment. Then it resumes strobing.
The cursor flickers between being an arrow and a pinwheel.
Occasionally, it will stop to ask for the laptop's password -- but proper entry of such only returns to the "strobing" screens.
Occasionally, dialogue boxes will appear/strobe on right side of screen -- such as for McAfee "trial expiring" or something. But engaging with those boxes (e.g. clicking Cancel or [X]) only resumes the "strobing."
Have tries reboots, overnight rest. Did not remove battery yet, as some forums suggest for "blank" screens.