Need helping upgrading my power supply

I have an HP Media Center PC that currently has a 300W PSU, but am looking to upgrade this to 500W because I will be adding an nVidia GeForce GTS 250 video card in the near future.

I'm trying to find something between $50-$110 that has these dimensions (or smaller): 6" (15.25cm) x 5" (12.7cm) x 3.25" (8.25cm). It needs to have at least one (two would be nice though!) 12v rail that runs at minimum of 24A.

My mobo is ASUS model: M2N68-LA (aka HP model: Narra2-GL8E).

Doubt that it makes a difference, but my pc is running Windows Vista Ultimate.

 

Corsair 650w
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005
52a on 12v rail this is a very popular PSU and will definitely last long
Also have a look at this OCZ 600w
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341017

Corsair and OCZ are both well known quality brands
Up to you now what you choose

Dacads

 

I like the Antec earthwatts EA500 500W which powers a quad 4GB rig with a pair of 9800GTs. Plenty of power.

 

Decided to go for the OCZ PSU.

Thank you both for your help.

 

Okay..so after a lot of forcing cables around, I managed to fit the PSU into my not-so-big HP case. Now, when I turn the computer on, my monitor claims that it is not receiving a signal. My GeForce 8600 GT is currently connected to the monitor via DVI cable, and I have never had any problems with it before...

I plugged in SATA and power cables for my HDD, DVDRW, and BD drive as well as the 20+4 pin into the mobo and the 4 pin to the CPU.

Did I miss something during my hardware installation?

 

Some 8600GT video cards have their own power connectors. If the card is not plugged into the power supply, it will not work correctly. Video cards from that era have one of three different power connectors: one looks like a 4pin floppy drive power connector, one looks like a std 4pin molex connector (like you'd see on an IDE hard drive or CD/DVD drive) or a 6pin PCI-Express power connector like this:

http://forums.majorgeeks.com/attachment.php?attachmentid=114429&d=1242665763

Also, since you had some "forcing" of cables, it's possible that something else got loose. Check all other connections and make sure they're all secure (both power and data connections to ALL devices including the motherboard).

 

I'm pretty sure I have one of the older 8600 GT's; it does not have a separate power connector. I'll recheck connections to other components as soon as I get a chance. In the mean time, any other suggestions?

 

Solved the problem by swapping out the power supply cable; I had been using my old one before, not the one shipped with OCZ.