Looks like the monitor has gone bad.
That unit has a 3 yr warranty so if that fits contact samsung and have a chat.
Support Phone: 1-800-726-7864
Went black but came back then flickered but came back. Now the monitor goes black after a few seconds or minutes & the front LED touch lights stop working. The CPU thinks it is still on and working fine but wont turn back on until unplugged & plugged back in. Have an older & much cheaper SyncMaster 2494 that is working fine, is the P2770H a lemon?