Can someone explain power supplies to me?

[mwp]

I've done some research, but none of it seems to cleary define issues for someone who does not have an engineering degree.

Here's what I'm working with:

asrock 775 dual-vsta motherboard w/ v2.4 bios
c2d e6300 1.86g processor
2x1 pc2 5400 ram
400gb maxtor sata hd
diamond ati radeon x1600pro agp graphics card
old sb live sound card swapped out from an old dell
one cd/dvd combo drive previously used in the old pc

Once I get this silly thing running correctly, I'll be adding a cd-rom drive, a second hard drive, maybe a card reader, and running a usb multifunction printer and a few other usb devices off it.

I'm powering this with an antec neo he 550w power supply, which has three +12v circuits. I have the motherboard, graphics card hard drive and cd-rom each on their own line, with nothing else drawing power from it.

I've read that the amps available on the "+12v rail" can be more important than the total wattage. I don't understand whether this psu having three 12v output circuits is a good thing or a bad thing, and I don't know if I have a power supply that's correct for my system.

I'm having all sorts of odd errors popping up, soem that seem to be due to bad driver installations (which I've fixed), software (which I'm powerless to do anything about except not use), possibly memory (although I've tested it and it seems to be okay), and now my dvd-rom drive just sometimes doesn't respond ... the eject button doesn't work, it doesn't recognize disc in the drive, etc.).

This feels to some degree like it's a power supply problem because I was having similar issues with an earlier power supply in the old computer that quit when I upgraded the supply.

but I just don't understand enough about how power supplies work to know how to make a correct decision about which to buy.

Thanks so much to anyone who can help me understand what I should be looking for.

[johnny_quest]

That supply seems to be adequate so I couldn't say if it was the cause of the problems, sounds unlikely...

wattage is simply voltage times current. Since your voltage doesn't change, wattage will increase proportionally to current.. so high wattage means high current...

[jlreich]

Having two or more 12v rails has been accepted as a good thing, even required, for quite awhile now, but there has been some debate about the matter lately.

But nothing in your system is particularly power hungry so lack of power is not the issue. And Antec is a good brand of PSU. Although any brand can have a bad unit go out. ;)

Start with replacing the CMOS battery. The one that comes on the mobo is often several years old. I have seen dead or dying CMOS batteries cause many strange problems. And for a few bucks it's worth it to rule that out.

It is, however, typical symptoms of a bad power supply. You can swap in another known good power supply, test the PSU with a PSU tester that can be purchased at your local computer shop for less than $20, or use a multimeter to test it manually. The latter is preferred, but somewhat dangerous to your system if you were to cross the wires.

It can also be a bad component. If you can't test the PSU, or the PSU test OK, I suggest doing a bare bones boot. Remove everything from the system, leave only CPU/HSF, 1 stick of memory, video card/monitor. In your case I would leave you hard drive in so you can boot windows to see if everything is working well or not.

If everything seems to be running fine, start adding in components one at a time and boot the system until the problems return. Once the problems return you know the last components you installed is the culprit.

The mobo could be shorting out slightly on the case. While doing a bare bones boot, take the mobo out of the case and set it on a non conductive surface while testing it.

It could also be a bad motherboard. But the only way to find that out is to test everything else, or install your components in another compatible motherboard.