they are pretty easy to see with the naked eye. im new at this but there is 2 types of dead pixels, the type that is dark and the ones that are bright.
1 open paint and paint it white and full screen. any black dots are dead pixels.
2 open paint and paint it black any pink/read pixels are dead...
if your using windows try using the regular windows "screen resolution" option when you right click on the desktop. i believe there was a option there to change which one is which.
if your not windows then sorry cant help other than just keep trying cause i know i did it before.