Greetings,
 
I have a question that perhaps someone in this group might know the answer to.
 
My family's media-PC is an Athlon XP 2000+ (at 1.67GHz with 1GB of Ram) on an MSI KM2M Combo-L mobo. This past holiday season I found that DVD burning would occasionally result in a sudden system shutdown (no "Shutting down", just black and quiet).
 
I thought I'd put a new PSU into my rig in order to relieve some of the load-stress, which I've heard is something of a concern on an older system with many drives and peripherals. I purchased an Antec Earthwatts 500w PSU hoping to relieve that stress, but found that my mobo may not support this.
 
My bios and other system drivers are all up to date, but I'm unsure where to go to find out about high wattage support. The gentleman at Antec recommended that I see if the bios supports it. After browsing around the (limited) bios menu, I can't see anything. Am I out of luck? Do I need to get a smaller wattage power-supply?
 
Let me know if there is any additional information that I can use to elucidate further.
 
Thanks in advance,
DocBadwrench

As far as I know it should work.  I used a Corsair VX450 in a computer with an MSI KT6V-LSR that had an Athlon XP 2800+.  My board is newer than yours I believe so I wouldn't say that guarantees that yours will function.  Hopefully someone who is better versed in ATX specifications can give you a better response.
 
-mcg

In that case, I am cautiously hopeful that my money isn't badly spent. If I'm remembering correctly, there isn't a "negative 5" pin in the higher watt power supplies from Antec. I am not sure what that information means, of course, but I figured I could offer just a bit more information.
 
Thanks for your thoughts, CommGen.

Ive never had any issues like this before, to my knowledge its doesnt matter about the size of the PSU just as long as it meets ATX standards, which all do.

I'm with Chookman here on that. Are you unable to boot up with the new PSU? What are the symptoms?

Basically, I install the PSU, hook everything up, then boot up.  Then the PC lights flicker briefly before going completely dead.  This all happens in about a half-second. Then I have to power-off the PSU (at the rear of the PC) and turn it back on before using the standard PC power switch.
 
When I called the folks at Antec, the tech said something about that "negative 5" thing I mentioned.  When I swapped my 320w back in the PC works fine, though I suspect the problems I had last Christmas will materialize again.
 
Can any of you recommend some techie-information sources I could read up on?  I had thought (originally) that it wouldn't matter if I got a beefy PSU - compatibility-wise. I'm glad I am not along in making that assumption. Thanks to all of you, thus far, for your help - I'm sure it will pay off in the end.

There's always a chance the new PSU could be a bad unit. Is there any other computer you can test it on?

I am hesitant to try to hook it up to my other computer (just because it's a huge pain), but if it's helpful, this is a straight-outta-the-box PSU I bought at Circuit City. I don't suspect there are any issues.
 
Of course, there could be an outside chance - I certainly have to keep that possibility in mind.
 
As an added note, should I try posting something in another forum here at Tom's Hardware?  I'm new to the community, but it's pretty legendary (in internet terms) so I figure you folks have the best odds of helping me with this.  

I attempted to hook my PSU up to an additional PC of mine and found that it wouldn't work with *that* either. So I returned the PSU to get a replacement, and *that* doesn't work either.  Currently, I have a brand-spanking-new Antec 500w power supply that I can't use in any way.
 
Admist all the opening, connecting and reconnecting the computer, I discovered that the CPU heatsync was caked with dust. Also, the CPU fan didn't work at all, so I think I know where the sudden, unexplained shutdowns were occurring.
 
However, when I tried to replace the fan/heatsync, the plastic on the mobo (that it was attached to) snapped off.  So now I need a new mobo that will accept my CPU and Ram (same as the KM2M).
 
Do any of you have any thoughts as to what mobo I should attempt to find? Perhaps one that can make use of this PSU?  I've been out of the systembuilding loop so I am having questions about where to start.