Just got my Spectre, followed instructions, plugged in etc and notice the cursor was sporadic - kept jumping to the top of the screen, spent over two hour messing around looking for updates - the HP auto update thingy didn't work. Windows update worked but nothing solved the issue.
Was about to return it to its box to send it back and i plugged the charging cable - Problem gone!!.
I thought maybe some earthing or something, but realized the screen went dimmer at the same time the problem went away.
Plugged back in and screen came on to 100% - problem back - switched screen to 75% problem gone!!
Have I got a fault laptop? should I return it? Bought it through amazon so I can easily return it.
Hopes this helps some else as I coudn't find anything by a google search.