shaX 07

I have an HP Media Center M8430F desktop PC and after I moved the PC wouldn't boot up.. It turns on, but the OS doesn't boot and the monitor says "No Input". I checked all the connections and everything is hooked up properly (I'm a network administrator by profession).

Last night I decided to take the Hard drive out and stand it vertically and see if gravity would allow the SATA cables to stay in place better and it actually booted up and worked fine all night. I put the HD back in just now and it's back to not booting up.

The SATA cables for the HD and the DVD drive are both very loose and don't stay in well at all. The Power cables are the same way, they fall out with the slightest touch and i'm almost positive this is the problem..

If anyone has any other theories please feel free to chime in. I've order some new SATA cables and they should be here tomorrow.

The only thing i'm worried about is if it is the power cables, how can I replace those without replacing the power supply? Aren't they wired into the supply?