WHY

Hi guys having problems with adding a graphics card to my machine; probably something I've done.

My PC (I'm a student and poor): medion akoya e1006D
Card: MSI R9 270X GAMING ITX Edition 2GB GDDR5 DVI HDMI Dual Mini DisplayPort PCI-E Graphics Card

Needed a seperate power supply because required 500w power. Bought a power supply and jumped it with the green and black.

Power Supply:  	CIT Gold 500W Fully Wired Efficient Power Supply

Then thought the heatsink was in the way and bought a PCI-e extender. Still not avail. Have changed the graphics in BIOS to PEG but not output to monitor and I can't see anything in device manager :((

What have I done wrong internet!