go to this website (found online)
http://jasonfarrell.com/misc/deadpixeltest.php
press black..press F11 for fullscreen..off the lights...
snap the photo with camera..you'll see the blb issues.
other than that, i use other color white red green blue to find dead pixel..
but do be warned, once u saw the dead pixel, it will be forever as u will keep notice it..
im still in contact with acer sg on this issues...they are not very responsive...
just worried they'll say "warranty doesnt cover this, u got the monitor its ur luck bye2"