These could be brought on by many issues and really happen at any time. The damage they trigger is dependent on the power of the surge and can be something from a blown fuse to completely frying the within of your pc with accompanying smoke (as was noted theft prevention system in Darwin a couple of many years ago). In all cases investing in a proper surge protector is essential. You'd be looking to invest around the $70 to $90 mark for a five to 7 port protector. Some leads to of electrical surges ...