Display flashed and stopped working.

Samsung C24RG50 curved monitor flashed momentarily in the left lower corner and stopped working. Now, a bright whitish oval spot the size of about one by two centimeters is seen in that corner when the display is on. It looks like the display is burned in that spot. When turning on, colorful horizontal lines/strips appear on the display momentarily and disappear, but no picture on the display. The backlight works fine, though. What are possible reasons? I do have the equipment needed in my electronics lab for testing, but would anyone suggest where to start?