I have XPS 8500 with windows 8.1 with a Dell S2340M monitor which a couple times a day goes black for a few seconds and then comes back on . I have the most updated video drivers as well as drivers for my monitor . I have ran the Dell self diagnostics test in Windows as well as in BIOS and has not found anything . I have also ran the monitor self diagnostics and it did not find anything . This morning it did something a little different before it went black, it changed the resolution on the screen showing much larger letters on the screen while I was working . I have a VGA cable hooked into a VGA extension cable that runs to the PC . I swapped the VGA cable going to the extension which is when for the first time it changed the resolution on screen before it went blank . That's when I decided to put the original VGA cable back on monitor that came with it . The only thing I have not tested is the extension cable that is hooked to the VGA cable or swapping monitors . The only reason I have not swapped monitors is because it is intermittent and it may not do it for a while . Anyone had this happen before and if so do you have a recommended fix . I have read somewhere it could be capacitors going bad , video card but have not read anything about cables