shutting down

[larryddd]

morning all I think I need a bit of advice if some kind soul would help me.my computer started going to a back screen for about 3 seconds,just before it comes back on there's a small blue screen in the middle with Dell in it (dell is my computer monitor)sometimes its a couple of times in five minutes and other times there's a gap of twenty minutes before it does it again.the small blue screen in the black is the same window you get when your closing down.my first thoughts is my monitor is starting to go (its seven years old now)prob time for a new one. there's not error messages coming up,no driver problems.anyone have any ideas ? I've checked the cables connecting monitor and computer and have given the computer case mild blow out(lungs)but will be getting a can of compressed air today to give it a better clean.not really keen to get inside the box to look at switches or anything. don't have a spare monitor to try but have to admit with my limited knowledge I'm leaning towards a monitor problem.thanks for taking the time to read this

 

[larryddd]

update

hi guys just an update on my above post and a bit of a puzzle.the problem I had started after the workmen started working on the house,I know they shifted the bt line slightly.but about an hour ago I unplugged my internet and ran my computer in offline mode, and I've run skyrim to the past hour with not problems.if there was something wrong with my monitor or cable would not the problem carry on,even if I was offline/online. my skybox is showing power,internet and wireless all normal when I'm online. maybe someone could shed some light on it.thanks Edit forget it problems back even in offline mode.back to square one