+12V reading is too low


Sep 28, 2004
Got a little problem with a brand new 450W power supply...
I bought a new gaming case with a 450W power supply, and installed everything properly. However, when I turn my computer on, it might run for 5 minutes or it might run for 10 minutes before completely shutting off. I Tried my old power supply (250W) and it works flawlessly. Being the determined geek that I am, I put the 450W back to troubleshoot, then went into the BIOS to monitor the temperature levels. Sure enough, the +12V Voltage was in the red (goes down to about 11.20V), whereas with my old 250W power supply, it was always around 11.70V), and I'd leave it on 24/7 without any problems. I assume that means the CPU is not getting enough voltage. Is there a way I can correct this? Or do I have to get the power supply exchanged? And by the way, the power supply is made specifically for a P4.
The labels on the power supply are as follows:
DC Output (MAX):
+5V -5V +12V -12V +3.3V +5VSB
36A 0.3A 18A 0.8A 31A 2.0A

P4 3.0E GHz
Asus P4S800, DDR 400, AGP 8X
512 MB DDR Micron Technology
256 MB DDR GeForce FX5600 XT
120 GB Maxtor HD
80 GB Maxtor HD
Cicero CD-RW, 52x24x52<P ID="edit"><FONT SIZE=-1><EM>Edited by Verizon_DSL_Tech on 09/30/04 06:26 PM.</EM></FONT></P>


Sep 12, 2001
You need a new power supply, dont get folled by power supplys that say P4 or AMD approved, that only means that can supply the required current on the 12v line. That does not mean they can keep the 12v line stable.

It is important to invest money in your power supply my power supplys cost £100 for 1 and £70 for the other (in US $ thats about $140 and $95? rough guess). Dont buy any cheap crap, it will either cause instability or conk out on you within a few months.


Aug 30, 2004
Go got yourself a quality PSU and that will probably solve your problem. I have two PSU and they both work great, but one is generic. The generic came with the case, but I have the option of choosing 550W instead of the lower rating. I alway choose 500W or higher for generic to give them more headroom and beside they tend to be a lot cheaper.
The new PSU I just got today is Fotron Source Power and rated at 400W with ample of AMP. The FSP weight 3X more than my generic PSU. I'm guessing I'm paying more because it weight more, but most of the time a quality PSU weight more over generic. Believe or not, the generic cost only $17.00 vs. $60.00 for the FSP.
Sometimes, people buy all the quality parts, but neglect the PSU and the worse part is, their computer run unstable. A quality PSU is a must for today hungry components.


Sep 28, 2004
Thanks for the great advise. I got the same thing from overclockers.com. The 250W PS was one that I bought from Radio Shack for $60 (CND), which would explain why it works so well. I think I'm going to go ahead and invest in a good power supply. I have this tentency to burn more computer components than I do CDs...


RS has great parts, like capacitors and such, but I do not equate them with great components and gadgets.
Usually, they have lower line stuff.
But some parts they have are hard to get, except from mail order.

Try everything...
Do not be afraid of failure, for this is how we learn and grow...
Live life to the fullest...
Do not regret what you have not yet done!!!