How do I figure which psu/power supply to buy for computer?

I have a computer, Presario CQ5210F, and my graphics card needs a 300watt power supply. The comp currently has 250Watt.



-Can I change it? How do I find out if the motherboard can handle it? No manuals were included.



-If I can change it, how high should I go, can I do 300 or 350? And how do I change it without potentially damaging my computer?



Thank you for any and all help.How do I figure which psu/power supply to buy for computer?
go here http://educations.newegg.com/tool/psucal

its really helpful when building a pc

its a power supply calculatorHow do I figure which psu/power supply to buy for computer?
COMPAQ PRESARIO CQ5210F DESKTOP PC

has Part 5188-2622

250-watt (max) power supply (Zinfandel), Bestec ATX-250-12V

http://partsurfer.hp.com/Search.aspx?typ



ATX means it is ATX size.



FSP Group ATX350

http://www.newegg.com/Product/Product.as



Replacing the Power Supply

http://h10025.www1.hp.com/ewfrf/wc/docum



Some power supplies over 700 watts may be longer. That is, go deeper into case. The power supply won't use more watts than the load needs.How do I figure which psu/power supply to buy for computer?
OK, I looked up the specifications for your motherboard. Your motherboard will accept any PCI-Express or PCI-Express 2.0 video card, which is a good thing. Your motherboard requires a 24-pin ATX power connector and a 4-pin ATX CPU power connector. Your new video card will likely require a 6-pin PCI-Express power Connector.



You've found out somehow that your graphics card needs a 300W power supply. This is likely the *minimum* recommended wattage for the power supply. Any good quality brand name 300W power supply would likely work OK. I'm going to suggest you use a 400W or slightly larger power supply, though. The problem with sizing power supplies by total wattage rating is that you don't know how much power will be pulled off of each individual voltage rail. And it's the individual voltage rails that matter. That's why it's a good idea to not use the *minimum* size of power supply.



Keeping that in mind, I'd recommend you go with the following for a power supply replacement:

http://www.newegg.com/Product/Product.as

FSP is one of the better quality brands of power supplies. And while you can certainly find a cheaper power supply that will work, you aren't going to spend *significantly* less than 40 bucks unless the power supply you buy is truly junk quality.



To change the power supply...

1) Unplug computer from wall outlet (duh)

2) Follow all cables from power supply to see where they connect. Write this information down somewhere (make a list of all connections, so you won't miss something on reassembly)

3) Carefully disconnect all power supply cables from motherboard, drives, cooling fans, whatever else the power supply is connected to.

4) Unscrew the four screws on the back of the computer that hold the old power supply in place. As you are doing this, you might need to support the power supply with your hand (if necessary) to make sure it doesn't fall out and land on something you don't want a power supply to damage.

5) Carefully extract the old power supply from the case, making sure none of the cables get caught on anything.

6) (obviously) Mount the new power supply, securing it with the same four screws you removed in step 4.

7) Referring back to the list you made in step 2, make all necessary connections to motherboard, drives, cooling fans (if necessary), etc.

8) If you haven't installed your new video card yet, do that while the case is still open. Also, don't forget to hook up the 6-pin PCI-Express power connector from the power supply to your video card, if your new video card needs it.

9) (obviously) Plug the computer into the wall outlet. If the new power supply has a power switch ON the power supply, make sure that is turned on.



You are done. :)