NO VGA Signal

One of our staff was trying to plugin a extra speaker to his machine (Running XP Professions) when he encountered a NO VGA Signal
Machine will look like starting but monitor will show an error NO VGA Signal before going blank

Changing Monitor did not help

The problem was somehow his RAM was moved and removing it and adding it again works !

I wonder why this Branded Desktops from COMPAQ has so poor Inetnals that adding a speaker wire will make RAMS moved its place