Asus 9800GT causing monitor problems

[RagingRabbits]

ok you see I have a pc the specs below

Motherboard : Asus B75-MA
Ram: 2Gb
PSU :520watts
CPU :i5 3570

so I can start the pc without a graphic card but whenever i insert my Asus 9800GT the monitor does not detect my pc so the monitor goes to power saving mode , but if I take out the graphic card the pc starts fine again . Please help me I really want to use my Asus 9800GT.

 

[GhosT_Hv]

9800GT requires external power supply.
check whether you've connected your PCIe power connector to your GPU or not ?
Is your card is working on other PCs, or your card is dead ?

 

[gameboy1998]

Also wehn you insert the graphic card you have to connect the monitor to the graphic card not the mothereboard.