"Do not connect while pc is on" nzxt s340 case

[JackMerridew]

Just to start I'm not really a computer guy; I saw this wire on my case with the sticker on it " do not connect while pc is on" Plugged in my new power supply and nothing worked (I plugged this wire in before I tested everything.)


I changed power supply and everything worked fine, until I was putting the old power supply into the case and put the wire in again, now no power. What was that wire for and is my hardware now broken because of it?

 

[Someone Somewhere]

Pics, please.

Suggest reading through this, too: http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems