Power supply dead (I think)

Hardware and technical stuff
1

Last night we had a thunderstorm (one of many this spring).

This morning, one of the PCs I use didn’t work. (It worked fine the last time I used it, either yesterday or perhaps a bit earlier).

The power supply fan didn’t even kick in when I tried to start it.

Oddly, another PC that I think is essentially the same on power components (Antec case and power supply) works fine, even though both were attached to the same power strip. The power strip has a light indicating that its protection is working, for whatever that’s worth.

So, I disconnected the power supply in the bad unit and took it out, which was a chore - lots of connections (I hope I get them back right), and the power supply was so inaccessible in this case that I had to pop the rivets and basically bend and remove a support brace to give myself the room to get the power supply out. (My other choice would have been to remove the CPU heat sink/fan, but I didn’t want to have to do the whole thermal paste thing again to get it back on afterwards).

So now I’ve got the power supply loose and unconnected. When I plug it in to a power outlet, the fan does not turn on - I hear a mid pitched, but quiet in volume, whine it is plugged in and the switch is on. When I unplug it, the whine persists for maybe 5-10 seconds, then dies out.

I’m not even sure if a power supply is supposed to work normally if all (or at least some) of the assorted leads to the MB are unconnected.

So, of course I’m suspicious that the power supply is fried, but it’s possible that it’s something else. Where I’m at, there aren’t convenient and cheap suppliers of PC components - I’d have to go about 7 miles to the local Best Buy or Circuit City and buy a power supply that would likely cost 3X more than what it would cost from a decent internet supplier.

I’d like to get the system back up and running reasonably soon, with a minimum of hassle.

I can:

  1. Go to Best Buy and buy an overpriced new power supply, hope that works, and know it would likely be a pain to return if it doesn’t (and that I’d be paying a huge premium for it).
  2. Use my other system (which is the one I’m typing on now) as a swap system. I’m hesitant because I had to manhandle the one so much to get the old PS out, and I don’t really want to mess up my working system to try to get the new one working. (Again, reconnecting all the leads properly scares me and there’s a non-trivial chance I’ll mess things up somehow).
  3. Use a ~10 year old cheapo system I have in the closet as a swap system. I’d imagine its power supply has a much lower wattage than the one in my problem system. (The latter is 450 watts - the old system is probably in the 100-200 watt range). I don’t even know if old power systems will work in new systems (have the standard connections changed?)

If I was 100% sure that replacing the power supply would solve the problem, I would go to Best Buy or Circuit City and suck up the cost. Even if there was a 60% chance, that’d probably be the right approach. But if in fact one of many components (or several) could be fried, and I really should be going component by component to test them, then I’ll probably just bite the bullet and rip my working system apart to be able to use its components for swap testing in the broken unit.

BTW, I don’t really want to buy a new system - I would much prefer to fix the system I’ve got.

2

When a PSU is connected normally, it shouldn’t spin up until powered on, but you should be able to hook up
a lone harddrive or CD/DVD drive when not connected. The wires are bundled into groups. Maybe try a DVD drive on
a plug from each and see if it opens and shuts. It normally needs something to pull power before it gives any out, the stingy sod :)

Unless you have a crappy powersupply which doesn’t have unevenly shaped power connectors in the right places,
don’t worry about hooking it back up. It really is a piece of cake. One which takes long to digest.

3

I’m pretty sure modern power supplies don’t work if they aren’t attached to a MB. My recommendation would be to jump start it using this method. I’ve personally done this a few times, so I can attest it doesn’t always lead to electrocution. Seriously, if you are concerned about safety, you can measure the paper clip width with the PSU unplugged, & then grip the body of the paper clip with a pair of pliers that has insulated handles when doing the jump start.

If that method fails to produce power, you know at least the PSU is toast. Of course, other computer components might be as well.

Assuming the PSU is dead, I would choose the following option:
4) Be thrifty & use your swap system to buy a decent PSU from Newegg; you might be able to use expedited shipping & have the total be less than you’ll pay at Circuit City or Best Buy. Use the few days until it arrives to test the rest of components on the swap system, using the internet if necessary to learn how to do it with no case metal bending. It’s really not difficult to assemble a machine, & you are smarter than the average bear.

If your old system is truly 10 years old, option 3 is out - modern MBs need a 24-pin main connector to the PSU, & a very old PSU will only have a 20-pin. If you need to buy a new PSU, make sure it has either a 20+4-pin (allows for either 20 or 24 pin MBs) or a 24-pin connector for your MB. Newegg is very good about providing this information; I would hope the big chain stores would be as well.

4

PSUs are (relatively) cheap, just try a new one.

Oh, and don’t believe the hype. You do NOT need an umpteen-zigawatt PSU unless you have dual high end gaming video cards and a bleeding edge top of the line quad core CPU.

5

A new PSU seems to have cleared things up.

I initially bought a cheap one, but it only had one SATA output (I needed two). I ended up paying about $100 at Circuit City. Probably overpriced, but bearable. If I’d had to do all this via mail order it would have been a major pain…

6

you overpay double if you bought it for $100

7

Yeah, they had a ~$50 model that probably would have done the trick, but I’d already underbought once (got something that didn’t fit my needs). Given that the store is a bit of a drive from my house (round trip and time to exchange = perhaps 45-60 minutes for me), and that the pricier model claimed to be quiet and more energy efficient, I was willing to overpay a bit…