Help on finding new Power Supply

Ok so I've got an HP Pavilion Media Center for 4+ years. The power seemed to have died out on me however.

I tried turning the tower on like the usual one day but it wouldn't turn on. It just makes a weird click sound and then refuses to boot up.

When I hold onto the power button for a while the green len lights up but when I plug the cord in the lights in the room blink dimly for a second and then the computer doesn't turn on...

So I was guessing the power supply was too weak to support it anymore.
Anyone know what kind of specs I need to know about my computer before purchasing the right kind of power supply? And where can I access the information?

I'm a real big n00b with computers, the only thing I know what to do is installing RAM sticks

 

Well a bit of help with the specs would be appreciated. I guess you have upgraded the system when you say the psu cant support the system anymore?

You need to know what parts of the system you have, that use power. This includes, gfx cards, RAM, mobo, HDD's, CD/DVD drives, fans, any other cards, leds/CCT's and so forth. Basically everything draws power. I dont look at a psu if its under 600 watts for my systems but these have 1 or 2 power hungry gfx cards etc in them.

 

If you have a standard HP tower and have not made any major upgrades other than adding more memory, then a 350-400w power supply should be fine. Some HP models are a bit 'cramped' in the cases and require 'shorter' power supplies so they don't bash in to the back of the CDROM drives. So, without knowing the exact model of the PC, I'll recommend some good, basic power supplies that should be fine for your PC:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371005
http://www.newegg.com/Product/Product.aspx?Item=N82E16817103012 (I use this same unit as a 'shop' unit for all my quick-check and troubleshooting type stuff and it's been abused and still runs great after 2 years)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182006
http://www.newegg.com/Product/Product.aspx?Item=N82E16817338009 (this one would work if you need a "shorter" power supply)
Now, I'm sure I'll get a bunch of people harping on me about how 'weak' and 'low end' these units are. Any of these units will be fine for a basic system consisting of a MB, CPU, one or two hard drives, and one or two CD/DVD drives. These power supplies are in no way recommended for ANYTHING other than a basic system without high end graphics, multiple RAID setups, etc....

 

You can get detailed information about your PC from the HP support page: http://www.hp.com/#Support and you'd enter your model number in step 2. This should be on the front of the PC; some HPs have the model number down low near the bottom of the front of the case, some have it up at the top. A typical HP model name/number is something like "Pavilion a1230n" for example.

 

The weird click noise may be that the fan died on it and it overheated. Did you notice the click sound before? Most likely the PSU died.

 

Click on this link for a how-to guide on replacing the power supply. It's complete with step-by-step pictures and is very easy to follow and understand. With power supplies, replacing them is easy: just be sure to notice what is plugged in to the old power supply first, before you unplug everything and take it out; and remember that not every plug on the new unit will plug in to something. I have handled MANY phone calls from people replacing their first power supply who were all freaked out about having "all these extra connectors that don't go anywhere". I have seen people somehow manage to plug all kinds of things in to power supply connections because they assumed that if the connector was there, something MUST plug in to it....