Blank Screen on Monitor

[skt12]

Today I RMA'ed my GPU (Sapphire 5670 1Gddr5) but when i plug it in mobo and turn it on , CPU runs but there is absolutely nothing on monitor.
On board graphics works fine!!
My Specs -

CPU
AMD Athlon II X2 250 36 °C
Regor 45nm Technology
RAM
2.00 GB Single-Channel DDR2 @ 401MHz (6-6-6-18)
Motherboard
MSI K9N6PGM2-V2 (MS-7309) (CPU1) 40 °C
Graphics
V203HV (1600x900@59Hz)
nVidia video (MSI)

Kinda Old but will upgrade later!

If its under - wattage problem how much wattage does I require including any future upgrades!! (Casual gamer)

Also tried on another pc with 450w psu - Same Problem:-(

 

[ricardois]

What is your PSU, and what is your Video card ?

Have you plugged all the pci 6+2 pins to the GPU? (if the gpu you are reffering needs them.

Have you plugged your monitor to the Video card output instead of the motherboard output?

 

[skt12]

What is your PSU, and what is your Video card ?

Have you plugged all the pci 6+2 pins to the GPU? (if the gpu you are reffering needs them.

Have you plugged your monitor to the Video card output instead of the motherboard output?

Yep! Plugged monitor to GPU!! Prev Gpu (512 mb 5670 DDR5) worked fine!!