Help with Power supply

[Syps]

I just got a new 300 watt ATX power supply from CompUsa today, and was tryin to install it, but after I plugged everything in, my comp wouldn't boot.
The green LED on the motherboard turned on, and when I pressed the power button the fans moved like a centimeter, but then thats it.
I reinstalled the old power supply and all is good, so I know nothing is fried or anything, I think i just set it up wrong. Is there anything that I need to do other than plug the main power connection into the board, and hook up my hard drive, cd-rom, floppy etc to the power supply?

 

[DaiShan]

nothing special imo, they have it setup now so you can't mess it up really, just plug them into where they fit make sure they are all snug, espescially the one to the motherboard, if it doesn't work this time it may be that you have a defective psu

/edit make sure that the power button is securely connected to the right slot on the motherboard, sometimes it gets nudged.

 

[Scootin159]

What is the old PSU?
What is the basic system specs (Motherboard, CPU)?

I have a feeling that your new power supply might not be supplying enough power. While for baseline systems the CompUSA PSU's work fine, they are known to have difficulties in certain combinations (Like an ECS board & a fast Athlon CPU).

 

[Syps]

Asus A7v mobo, duron 650@900, my old power supply was a 250 and works fine, but I'm going to get a 1.4 tbird so i wanted a new PS, and figured i'd install it while I wait for the new processor. It shouldn't be a shortage of power, since my 250 is working fine. Is it a possibility though? Im not sure what brand my old 250 power supply is, it came with my enlight case, and it says MAX on the side.

 

[Scootin159]

<< Asus A7v mobo, duron 650@900, my old power supply was a 250 and works fine, but I'm going to get a 1.4 tbird so i wanted a new PS, and figured i'd install it while I wait for the new processor. It shouldn't be a shortage of power, since my 250 is working fine. Is it a possibility though? Im not sure what brand my old 250 power supply is, it came with my enlight case, and it says MAX on the side. >>



It's not really an issue of how many "total watts" your PSU can deliver. It's how many amps it can deliver at various voltage rails with how much stability. For instance a PSU delivering 20amps @ 12v and 2amps@ 5v will have a 250w rating (extreme case), but won't do you much good in a modern system. Even a PSU that can deliver 100amps on all the voltage rails, but has large fluctionations, will do poorly. Anyways, what I'm saying is that in theory it is possible for a 250w PSU to be 'better' than a 300w PSU.

However as far as solving your problem I would just say go with what works & return the 300w PSU to CompUSA (saying it doesn't work, should be enough for a return). I would then attempt to run the new CPU on the 250w PSU (although keep an eye on voltages as it very well may not be able to handle it), and plan on buying a nicer 300w model shortly thereafter.

 

[ShallowHal]

If you have a tester that might help. Otherwise I would take it back and have CompUSA check it out.
I'm assuming you did all the standard troubleshooting...

 

[Syps]

I think im going to take it back. My second question....is a PC power and cooling 300 watt power supply better than an enermax 350?

 

[ShallowHal]

I have the enermax 350. I have a xp 1700 with eppx 8hka mobo and everything is kosher. Get the enermax and everything will be fine. I'm sure there are others in this forum who have success stories with different power supplies but the enermax is great IMO.

 

[milagro]

make sure you use the correct voltage setting also 115 us instead of 230V elsewhere---kind of obvious but i didn't see anyone else mention it..