I had a power outage today that I think sent the power supply of one of my computers to the great electronics heap in the sky.
My understanding with power supplies is basically that it needs to physically fit (I’m pretty sure this is an ATX standard p.s.), the motherboard connector needs to be the right configuration, the overall wattage needs to be sufficient, and the various power outputs need to be of the correct type and quantity.
Am I missing anything details for when I go shopping tomorrow?
If it matters, this is an HP Pavilion m7167c media center PC (my main box and DVR) with, IIRC, an ASUS motherboard.
Just one thing. The cheap generic chinese-manufactured ones have a marked tendency to crap out. Spending an extra $20 on a reputable brand (likely also manufactured in China, but with a level of quality control) is usually worth it. I’m partial to Seasonic, but there’s lots of makers of good quality, reasonably priced PSUs. Antec, OCZ, and PC Power & Cooling all have power supplies that show up in the $25-50 range on Newegg.
Get a modular. They’re PSUs that allow you to connect only the cables you actually need instead of 25 different pieces of electronic spaghetti in your system. I will only ever buy modulars now.
You should be aware that big PC manufacturers like HP and Dell sometimes will use non-standard form-factors for their PSUs, or they may use odd standards like FlexATX, or SFX.
Plus, the ATX standard is treated more like a guideline these days, so a lot of aftermarket PSUs may be longer than will comfortably fit in your case.
I’d measure your PSU, and see if you can get the dimensions of any PSU you are looking at to make sure it will fit.
While I agree with DWMarch that modular PSUs are pretty awesome, especially if you are a tinkerer, if you plan on keeping the rest of the system stock and never upgrading, the benefit of a modular is simply 5 minutes less installation time, and maybe slightly better airflow due to less cables. But at a 50% (or more) price premium, it may or may not be worth it for you.
For what it’s worth, here are the two power supplies I’ve bought in recent years that have served me pretty well: this one’s a modular RaidMax in my wife’s PC, and this one’s a Rosewill (yes, a Rosewill) that has been rock-freaking solid for a couple years.
Wow, I just realized that RaidMax modular is on sale for wayyy cheap - so much for a price premium.
Though I should mention that this one doesn’t have plugs in the PSU itself - it has a short pigtail of cables terminating in plugs, and a bunch of longer cables you can plug in as needed.
One important idea you are missing is the idea of “rails.”
"In computer power supplies that have more than one +12V power rail, it is preferable for stability reasons to spread the power load over the 12V rails evenly to help avoid overloading one of the rails on the power supply.
* Multiple 12V power supply rails are separately current limited as a safety feature; they are not generated separately. Despite widespread belief to the contrary, this separation has no effect on mutual interference between supply rails.
* The ATX12V 2.x and EPS12V power supply standards defer to the IEC 60950 standard, which requires that no more than 240 volt-amps be present between any two accessible points. Thus, each wire must be current-limited to no more than 20 A; typical supplies guarantee 18 A without triggering the current limit. Power supplies capable of delivering more than 18 A at 12 V connect wires in groups to two or more current sensors which will shut down the supply if excess current flows. Unlike a fuse or circuit breaker, these limits reset as soon as the overload is removed.
* Because of the above standards, almost all high-power supplies claim to implement separate rails, however this claim is often false; many omit the necessary current-limit circuitry,[6] both for cost reasons and because it is an irritation to customers.[7] (The lack is sometimes advertised as a feature under names like "rail fusion" or "current sharing".)"
Imho, this is only important if you are running multiple video cards. If so, check for “SLI Ready!” or “Crossfire Ready” on the list of features.
KneadToKnow, I just noticed you said you were going out shopping tomorrow.
Word of advice - if you’re shopping at brick and mortar stores, don’t buy something like a power supply from a big box retailer like Best Buy. They usually carry either crap low-end components (and you don’t want a cheaply made power supply) or reputable brands like Antec and RaidMAX, but jacked up 100% over a place like newegg.
I don’t think they have anything like a Fry’s in your neck of the woods (huge computer-parts/electronics store) - if not, and if you can at all afford to wait, order from newegg, or tigerdirect, and save some $$.
I have some mom & pop type computer shops around here, Prince, but I fear they, too, will tend to stock junk. I think the first thing I’ll buy is an actual power supply tester.
The last time I bought a power supply was to upgrade my girlfriend’s computer and it was an Ultra. How’s their rep?
If the mom & pop shop has managed to stay in business for several years they are not likely to be selling junk nor charging out of line prices. They can get you anything you want to order within a few days but the parts they choose to use on a daily basis have been chosen because they are a good value.
FWIW, my local shop defaults to Antec for power supplies.
Seconding this. Get the manual or field service manual from the HP site so you can see if a standard ATX will even fit. It will list the wattage. Get the same or more wattage, dont go lower.
I checked a couple of power supply replacement parts sites and they’ve led me to believe that it is a standard ATX p.s., but I will take measurements to be sure.
I also just bought a p.s. tester so tonight I can give it a thorough going-over.
Well, I pulled it out and tested it, and it says one of the 12v outputs is below acceptable voltage.
Strangely, when I plug the 4-pin CPU power connector in, that changes to being within acceptable voltage. Still, I’m assuming it’s bad based on the first condition.
Also, the p.s. labeling describes it as ATX 300W, so I still feel relatively safe in assuming it’s a standard ATX form factor. It also matches up with another p.s. I have on hand which (a) I know to be a standard ATX form factor and (b) also reads unacceptable voltage on one of the 12v outputs until I plug the 4-pin CPU connector in.
Still curious if anyone can say what Ultra’s rep as a p.s. manufacturer is.
That’s fairly normal. Most PSUs need a minimal load before they operate correctly (tho the expensive ones have this load built-in). Without putting out a load, I’m not sure if this tester is effective. (Tho i think it did prove you have an ATX)
I’ve had good luck with Enermax Liberty modular power supplies. Two computers, six years total, often left on for days at a time. A power supply is not a sexy component to sink money into, but spending extra to get a quality unit is money very well spent. Newegg user ratings are a good barometer, even if you buy elsewhere. Happy shopping!
Until I tested it, I would have said “jumping to conclusions based on experience,” I guess.
There’s an excellent site with troubleshooting flowcharts, though, and following that down, given that I have no way to test the switch, and assuming that a mere electrical outage could not have altered the geometry of my case, I’m forced to guess that it’s the power supply.
So what happens to your computer, exactly? Doesn’t turn on? Btw, testing the switch is easy. Just take a screwdriver and short the two leads it connects to.
Can you find the fuse inside you PSU to see if it’s burned?
It is. But don’t get carried away. Some PSUs are so overpriced you’d think they were ‘enthusiast ram.’ $50 is a good ceiling (vs $20).
You might justify a tad more than that, if you want a higher power rating, or the modular feature. I’m using an Enermax Noisetaker that I’ve had for several years, and it’s working well. I note that on newegg, Enermax has only two models < $50 (350 and 405W). The mentioned Liberty (400W version) is listed at $85.99. Antec has 3 for just under $50, also the lower wattage end of their line.
One place the cheap PSUs cut corners is one the fan quality. The power supply fan is heavier duty than the cheap little fans you use in your case, and good fans add to the price. When your cheapo PSU gives out, quite often the fan crapped out and it fried.
Yeah, they make fanless power supplies. I don’t trust 'em.