just plugged a C13 power lead Extension into the back of the tower and there was a blue flash . now the tower wont boot up but the second tower on the extension C13 cable is working fine . neither PC's were booted up at the time of the incident by the way any ideas where I should look for the problem or have I actually done something bad ? the second tower is being fed power through the C13 extension socket of the tower that wont boot