I apologize if this has already been covered.  My Alienware X51 was working just fine.  But I came back from vacation and now it won't turn on at all.  I guess I should've just left it on while I was away.  Because now, nothing is working.  The blue light on the AC adapter not on like usual.  Thus, the white light on the power button not on like usual.  In the past, I could just unplug/replug and get the needed blue light.   Do I need a new power cable AC adapter?  Are there equivalent types 100% compatible I could get at electronics store so I don't have to wait for one to get shipped to me? My laptop is slower so I'm looking to fix this ASAP.