Showing blue broad lines sometimes and sometime works really perfect.

I have no idea what should i do with this monitor. Sometime moniter works perfect but some of the time it starts flickering and picture stucks. I try to change the modes and it starts again but after few minutes back to blue line and flicker

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0