Power supply problem??

I'm working on a generic desktop PC with an Intel E210882 mobo that's having some power issues. It has a 350W ATX switching power supply, with the 2nd 4-pin 12v power connector for the mobo. When the computer is powered up, the CPU fan runs for about a second or two, then shuts off, and the computer doesn't post. If I disconnect all the peripherals, and only connect the two power connectors to the mobo, it works fine (obviously it won't go past the post without an HDD though...). I don't have another ps to swap into the computer, and before I go buy another one I wanted to confirm that it actually was the ps causing the problem. I've tried a different HDD and it does the same thing... Any ideas?

 

I see it is an IDE drive you may have flipped the HD over I have done this a couple of times over the years.

 

No the cables are in the right way. On that topic, I also tried using a new IDE cable, but it didn't help.

 

Recheck your drive jumper settings.

 

Drive is good to go, it's on cable select. I'm not convinced it's the drive cause it's doing the exact same thing with another drive that I know is working.

 

It does sound like the PSU is struggling when it is loaded up. Without a HD, it should still POST - you should see the graphics GPU splash screen and everything up to where it tries to find a boot drive, then it will prompt for a disk.

Sadly, there really is no way for most users to test PSUs conclusively. See my canned text below on that.

Is that the original PSU that came with the computer? Have there been any hardware upgrades since new - such as adding RAM or new graphics card? Many factory made computers come with PSUs that are barely adequate from the beginning, and offer little to no head room for upgrades. Also, PSUs age and lose capacity over time. If you have more than one stick of RAM, you might try with just one, and disconnect all other extra devices (optical drives, USB devices, etc.) to see if it boots, otherwise, I think you will need to take your chances with a new PSU.
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To properly and conclusively test a power supply unit (PSU), it must be tested under various realistic "loads" then analyzed for excessive ripple and other anomalies. This is done by a qualified technician using an oscilloscope or power analyzer - sophisticated (and expensive) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronic repair facilities.

Fortunately, there are other options that are almost as good. I keep a FrozenCPU Ultimate PSU Tester in my tool bag when I am "in the field" and don't have a good spare power supply to swap in. While not a certain test, they are better than nothing. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you have a better chance of detecting a "failing" PSU, or one barely within specified ATX Form Factor Standard tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, it is not a true load or suitable for conclusive testing.

As mentioned, swapping in a known good supply is a tried and trued method of troubleshooting used for years, even by pros. Remove the "suspect" part and replace with a "known good" part and see if the problem goes away.

I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This requires poking (with some considerable force) two hard and sharp, highly conductive meter probes into the main power connector, deep in the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it. It is not worth the risk considering most multimeters, like plug-in testers, do not measure, or reveal any unwanted and potentially disruptive AC components to the DC voltages.

And remember, anything that plugs into the wall can kill. Do not open the power supply's case unless you are a qualified electronics technician. There are NO user serviceable parts inside a power supply.​