Windows 7 - PSU/mobo compatible???

So I tried putting this motherboard, Biostar A880G+ in a Dell Dimension 2300.
What I've already upgraded also:
RAM to DDR3
adapter to turn IDE HDD into a SATA connection
CPU to AMD Athlon II X2 245 Regor 2.9GHz AM3 65W Dual-Core
stock heatsink from an AMD Phenom II x6 1090T

Unfortunately, the board has a 24-pin socket for psu connection, whereas the Dell psu has a 20-pin connector. All I've read so far is that this shouldn't be a problem, "unless it's a Dell psu-" then maybe there will be a problem. I hooked everything up, and it wouldn't power on. Literally, I pushed the On button, and absolutely nothing whatsoever. It didn't even try to power on. Is there anything else I could check? What can I do???

There are issues between some Dell power supply units and the standard ATX motherboard and you probably need to buy a Dell to ATX Power Supply Converter as pictured here:

Adapter for Dell Power Supply

More excellent information here:

InformIT: Dell proprietary (non-standard) ATX design > Dell proprietary (non-standard) ATX design

It would appear that trying to match a non-Dell PSU with a Dell motherboard (and vice versa) can damage your motherboard and is Dell's way of ensuring you have to buy Dell PSUs if you want to upgrade your Dell computer.

I know this to be true because earlier this year I tried to upgrade the graphics and power supply on a Dell XPS 8100. The new power supply had a 20-pin connector while the Dell motherboard had a 24-pin socket.

When I switched on there was no power so I put the old power supply back in and returned the new PSU and graphics card for a refund.

The Dell from then on ran OK, but the CPU cooling fan cut in constantly so I contacted Dell about the issue who then replaced the motherboard, CPU and cooling fan. Coincidence or what? It would seem the new power supply had fried the motherboard.

This might help you.... 20pin to 24pin adapters ... if you try them just make sure you get the right one....20 to 24pin or 24 to 20pin

I did not see the above post b4 I posted! I'd go with ^^^ that!

I would cut the middle man out and buy a suitably rated standard ATX PSU (assuming that the current Dell one is a standard sized one), as PSUs included by many manufacturers such as Dell have only sufficient power capacity for the hardware that the system comes with.

Come to think of it, I did notice that when I was looking for the wattage, I didn't see ATX labeled anywhere. Although, there isn't much labeled on it at all. =/ So, SeaVixen, do you think that converter that jeepmann suggested will work for now?

It's 250W, and here's the peripherals:
cpu (65W)
1 HDD 7200RPM (tho with my luck lately I expect this to turn out shot --_--")
1 DVD drive 16x
1 CDR/W drive 40x
Biostar motherboard (can't find any power requirements)
2 GSkill 2GB DDR3 1333MHz
80mm fan 1800rpm
front 2 usb ports & headphone jack are unconnected
Do you think I could I get away with the 250W & just an adapter for a bit longer???

Ugh this was supposed to be a cheap way to boost my lil sister's computer, but with it being sooo old & the incompatibilities with Dell, the numbers keep going up.
Nonetheless, thanks for all the info, folks!

Nevermind, I checked the prices and the adapter is just as much as a new 350W psu! lol
Also ran the specs through a power calculator & came out with 272W, a suggestion of 299. 350 should keep well.

OK, thanks for the feedback. Pleased to hear you haven't incurred any further cost.

Well, a little bit. $15 for 350W power supply is pretty great though. =)

Can't argue with that, it's a good price. Hope it does the job for you.

This article is from 2002. I don't know whether Dell is still using nonstandard PSU wiring. However, the Dimension 2300 is also from around 2002, so the funny wiring may well apply. Even if the PSU was basically compatible, the A880G+ also needs a 4 pin +12V connector for the CPU. (It may be possible to kludge that up with a Molex adapter, but it'd be better to use a PSU designed for it.)

Does the 2300 also use the ribbon cable for the front panel buttons? That may complicate matters a bit.

I suggest not trying to use the Dell as the chassis for an upgrade. The 200W PSU is worthless. The machine as a whole doesn't bring a lot of value to the build.