Yeah I suppose your right.... but then again I'm used to the technical stuff.
The question suggests that this happens repeatedly. Ergo, it's not a cable issue unless something moves the cable.... from what was posted the most obvious being the mouse cable.
The system boots into the o/s and upon launch of an application the screen loses signal.
Given, true, it could be a faulty graphics card, however, usually a fault of that kind shows it's effects during boot.
Given the screen turns blank during launch of an application, the most common reason is a graphics setting that the system can't cope with. This is common with ATI cards and certain games.
But hey, I'm only a over qualified IT Admin who has a work record of over 11 years, currently finishing a MCIT to add to the list.
Sorry about the rant but it's been a hard day. Ian asked for extra info due to the question lacking it. I went with what I read. I don't run threw a step-by-step guide unless all else fails... besides I had this issue myself about 2 years ago... EVE had an issue with certain ATI cards being that a refresh command was invalidly called causing the loses of signal to the monitor. (Happened to alot of games tbh).