PC comes on and weird noised from PSU once plugged in - new power supply

matrophy · 12-24-2012, 04:17 PM

I replaced the power supply in my Dell PC with an aftermarket one (Athena brand) of higher wattage and once I installed it and connected everything, without pushing the on button, as soon as I plugged in the AC cord, the power light on the on button came on and horrendous noises which sounded like the hard drive clicking and whirring started right away. It could have been the PSU fan making the noise but it sounded more like a hard drive but real fast whirring and real loud clicking. I immediately unplugged the AC cord and reinstalled my old power supply. The PC started up normally and I had to push the on button to get it to start up.

I bench tested the new power supply by plugging it into an AC outlet and the blue light on the back came on but nothing else happened. I was under the impression that the PSU fan would come on in this case but it did not.

Does this point to a bad power supply or something in my installation? I am tempted to return the new PSU but I am reluctant to buy another one if it could have been an installation problem.

lehtv · 12-24-2012, 04:56 PM

Could be some serious capacitor or coil whine.

Why'd you go buy an Athena PSU, and exactly what model did you buy? Athena aren't good quality; whether it was faulty or not, I would return it and buy a real PSU.

VirtualLarry · 12-24-2012, 06:56 PM

Is this an older Dell that used a proprietary ATX connection? That could be the problem.

GAO · 12-24-2012, 10:14 PM

To answer your other question, power supplies won't start up, including the fan, unless plugged into a motherboard or power tester. This is because the Motherboard shorts two pins making a connection signaling the PSU it can turn on. So that is expected and doesn't mean it is dead.

ehume · 12-24-2012, 10:34 PM

It sounds like you have an older Dell with their proprietary PSU connections. Be grateful you didn't kill something.

Next time do some homework:

1. Find out what pin assignments your exact Dell uses. You ought to be able to find it on Wikipedia or a more general web search.

2. Do your homework on PSU's. Athena has an ugly rep. Take it back and don't buy another until you know what brands are reputable.

But in the end, you may have no other choice than to stick with what you have, or buy another Dell. One thing about Dell: they buy really good PSU's, often with Delta and San Ace fans in them. Why? They don't want the PSU to die so they must replace it.

I've had Dells die on me, but I always just replaced the rig: they were generally old by the time they died. Most were retired, though.

matrophy · 12-25-2012, 12:52 AM

Quote:

Originally Posted by lehtv

Could be some serious capacitor or coil whine.

Why'd you go buy an Athena PSU, and exactly what model did you buy? Athena aren't good quality; whether it was faulty or not, I would return it and buy a real PSU.

I could use a suggestion on what you would consider to be a good brand of PSU's.

matrophy · 12-25-2012, 01:00 AM

1. Find out what pin assignments your exact Dell uses. You ought to be able to find it on Wikipedia or a more general web search.

Once I know the pin assignments that my current Dell PSU uses, I'm not sure what to do with that info. Is that what I use to find a compatible aftermarket PSU?

lehtv · 12-25-2012, 07:59 AM

Quote:

Originally Posted by matrophy

I could use a suggestion on what you would consider to be a good brand of PSU's.

Antec, Corsair, PC Power & Cooling, Seasonic, XFX. There are decent units from other brands as well including Cooler Master, Thermaltake, Silverstone, Kingwin, OCZ etc. but you can't go wrong with the first ones.

For the budget oriented, Corsair CX series is a sure bet. Midrange: Antec Neo Eco, Antec Earthwatts, Antec HCG, Corsair TX, PC Power & Cooling MK III, most Seasonics, XFX everything. High end: Antec HCP, Corsair HX, Corsair AX, Seasonic X series.

You can also get a decent idea of what's what by browsing PSU reviews conducted by JonnyGuru and Hardwaresecrets.

Eureka · 12-25-2012, 04:14 PM

You must tell us what the older model of PSU was. Some Dell PSUs were custom made for them, so they have different pin-outs. For those PSU/Motherboards, you cannot just replace it with any other power supply.

Why did you replace your PSU at all? Was it failing?

bryanl · 12-25-2012, 04:46 PM

Quote:

Originally Posted by VirtualLarry

Is this an older Dell that used a proprietary ATX connection? That could be the problem.

Dell abandoned that connection over a decade ago. Those Dell motherboards had a second power connector, a single row of 12 flat pins for ground and +3.3V lines. Power supplies for such motherboards will have a pair of 6 pin connectors to match. Connecting a standard ATX power supply to such a motherboard will short every voltage line to ground.