Replacement for Nvidia Graphics card

My friend has a problem with a Dell Inspiron 531, AMD� Athlon� 64 X2 dual-core processor, Windows 7 HP 32bit, memory 4 GB, PCI Express connector one x16, PSU 300 watts. We need to replace the Graphics card that came with the machine which is Nvidia GeForce 8300GS, as it seems to have given up, the screen displays blue vertical lines!
I have been looking at a EVGA Nvidia 8400GS 512MB 32-Bit DDR3 Passive Graphics Card to replace the faulty Nvidia GeForce 8300GS, can someone with tech knowhow please advise if this card EVGA Nvidia 8400GS 512MB 32-Bit DDR3 Passive Graphics Card is a compatible card for the system or know of a graphics card that is a better replacement for the above system? Major concern is that the PSU is only 300 watts!
Any help would be greatly appreciated.

Dabs website dabs.com says minimum of a 300 Watt power supply for EVGA Nvidia 8400GS 512MB 32-Bit DDR3 Passive Graphics Card so power supply should be OK

Thanks for that wood49, it was very confusing as on EVGA own web site it recommended a 350 watt psu and on the same web site on an other page it said it was a 300watt!
Any way, its all done and dusted as I went ahead and fitted it and it works!