White dots

Sometimes on the black background of the monitor white point run. Happens every 2-5 minutes I notice a white pixel, which immediately disappears. The monitor was already repaired, with changed matrix due to the fact that the monitor has been flickering.Now in short confused, because in General, now is working fine, but confuse these manifestations of white pixels periodically( usually in games) and still have one dead pixel, but in my class monitors, it is not allowed. Do I need to call in garantiyku, or there will say they saw nothing and I've wasted your time? What can you recommend?