my son was on the computer the other night, after he'd been on a while he shouted to me saying that the monitor wasn't working, so as far as I know he's not touched anything he shouldn't have. When I went to have a look, it had power to it but the screen was black, as if it was turned off. I have since had a look to try and find out what's wrong with it. Have checked the cables, all ok, It is still black but can just to say see the start up screen but cannot see the cursor. Its an LG L1715s. Any advice as to what the problem may be? TIA. Mandy