There is a software problem with this phone that effects the external and internal display and also the ear piece your best bet is to contact Lg directly because the cell phone carriers can only do so much with the software problem mine has been repaired three times so I would diffently contact lg they don't know that there is a problem with the phone unless you tell them.
Did you try taking the battery off and putting it back on? That works for some phones. If it doesnt then, you should take it to a tech and have it repaired or replaced if you are still under your warranty.
I just got this phone today and it did the same thing. I can't get the outside display to work again. It worked fine and then I had to charge the battery and now it won't work. Is there an option to turn it back on or do I need to take it back already?