Issues with replacement PSU

[cloud32187]

So I've got this gateway dx-4300, its running windows 7 home 64bit.

The guy came in with the original issue of it not booting up. Turns out it was a bad PSU. I ordered the new PSU and i plugged it in and everything lights up and all is well. Then i go to shut down the computer in windows to install windows updates, then it goes to a black screen no POST no BIOS screen, holding down the power button doesn't turn it off either. I flip the power switch on the PSU and wait a minute or so, pc turns on fine again.

So here i figured i just got sent a faulty item, test it with my known good PSU and i can shut down and start up all day long. Went through with the return and got another one shipped to me.

....same issue. It boggles my mind because it works perfectly with my test PSU, so it seems pretty definite that the PSU is still to blame.

No idea whats going on, I've replaced the cmos battery, reset cmos, disconnected extra cards/usb devices etc, swapped out RAM, pretty much everything i can think of.

Any ideas are welcome, i mean, what are the chances i got 2 PSU's with the same exact issue?

(Here's the PSU in question: http://www.newegg.com/Product/Product.aspx?Item=17-152-032)

 

[seedubya]

Yes, it's possible, if they're of a batch and there's a manufacturing defect. Have you tried the psu in a different tower? Do you have any other psu around you can try, just to double verify?

Easiest thing to do is just buy a different model psu and install and return the others.

 

[jbartlett323]

With a $25 Raidmax? Very possible to get 2 DOA in a row. Also very likely to have 2 fail back-to-back. I'd look to increasing the quality of PSU.

I used to buy the cheap ones too, but they kept giving various weird issues. Everything from not booting to certain pieces of hardware not working to quick failures. Switched to Corsair CX430's and have not had an issue one since... Little more expensive for my clients, but we all sleep better knowing their is a quality product in their system. And if its not worth putting a quality PSU in, its not worth repairing and needs replaced...

 

[glennd]

it's possible the psu is under spec for the machine in question. does your test psu and the one you actually installed have the same power output rating?

 

[cloud32187]

it's possible the psu is under spec for the machine in question. does your test psu and the one you actually installed have the same power output rating?

The PSU that was in the machine was a 300W generic PSU from china. The only thing i can think of is that the max combined wattage on the 3.3v and 5v rails is 160w on the one that was in the desktop. The one i bought as a replacement says that its a combined wattage of 120w if im not mistaken (not in the office at the moment). Possibly that's the issue?

In response to the first post, i did end up trying another known good psu (300w), the combined wattage of the 3.3 and 5 rails was 140. Different outcome with this one, i shut it off in windows and it just would not power up at all after that.

 

[Altster]

I guess I'm seeing this issue from a different angle ATM.

Don't you have a retail store (Fry's comes to mind at the moment) that you can get all "touchy-feely" with to do a side-by-side comparison with several PSU's?

I tell people who are wanting to purchase "NEW" PSU's to shop somewhere like that (we have Fry's in my part of the world.) I also tell them to pick the "heaviest" (in weight) PSU they are interested in as generally the heavier the unit, the better the lifespan of said unit. Usually I suggest getting "as much as you can afford" in a replacement PSU because higher wattage is always a good thing - without going overboard, of course!

 

[ohio_grad_06]

If nothing else, get one of these. It's EVGA so you know at least it should not blow the computer sky high.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817438015

Higher wattage always better? I disagree to a point. I've bought 500 watt power supplies that were junk and then had 400 watt power supplies that lasted a while. Main thing I like to look at is the amperage on the 12v+ rail. If you are doing a gamer's system, I'd recommend doing some research, but corsair antec etc are the big guys. I've had good luck with the EVGA psu's though for their price. That one above is only 430 watts, but rated for 34 amps on a single 12v+ rail. The raidmax is 32, so not a horrible rating, but I know the name, however, I know evga a little better I feel and have installed power supplies, video cards from them etc so feel like their gear is reliable. But I agree, you start talking 25-30 for power supplies, you will probably get a couple that are iffy now and again.

 

[glricht]

I tell people who are wanting to purchase "NEW" PSU's to shop somewhere like that (we have Fry's in my part of the world.) I also tell them to pick the "heaviest" (in weight) PSU they are interested in as generally the heavier the unit, the better the lifespan of said unit. Usually I suggest getting "as much as you can afford" in a replacement PSU because higher wattage is always a good thing - without going overboard, of course!

Never thought about going for the "heavier" PSUs, but it's usually good practice to replace a PSU with one that's at least 100W larger. Many original PSUs are marginally sufficient, so replacing it with the same wattage simply delays another failure. For us, we'd replace a 300W PSU with at least a 400W, sometimes even a 500W depending on price.

 

[joydivision]

I know quite a bit about PSUs due to my limited electronics background and general research.

There are a lot of cheap crap from China which is not only faulty but dangerous. While Corsairs etc are also made in China you can have faith that they have systems in place to make sure the stuff they are importing is decent quality.

I prefer Corsairs as my number one choice (both the VX and CXs are very good) but not had any issues from Coolermaster ones either. I used to be a big fan of FSPs, and some very old ones still working in my system, however last year I was noticing a very high failure rate with FSPs so I no longer use them.

Another thing to remember is that Corsair etc don't make power supplies they just design and import them but they don't sell crap etc.

The big thing about PSUs is that wattage is not important, the ampage figure on each rail is far more useful. I've seen 400w cheap PSUs with 12 amps on the 12v rail which is nothing. Most decent 400w PSUs offer around 26-30amps at least. I have a basic Corsair VX450 in my hand right now, it 450w but offers 34amps on the 12v rail.

There have been tests done on the very cheap PSUs and often they blow up before you can put anything like the load they claim on them.

Some info here

http://www.youtube.com/watch?v=5NUz5rNzw1Q

Also if you can always try and get an 80+ certified PSU.

 

[kisk]

Have you ever thought that maybe you're not dealing with a PSU issue but a mobo issue? It honestly sounds like the CPU voltage input isn't being regulated correctly when coming through the P4. Have you tested cap ESR's, etc? Do you have a PCI post hex code tester to see how far you're getting through the post process?

 

[gikstar]

I don't know why, but a number of the power supplies that are carried by Newegg are not available at Fry's. I bought 2 Antecs in the past 3 days, a 450 and a 550 wt.
I like to check out the best rated in the size that I'm looking for on Newegg and then get that, but Frys doesn't always have that model. You don't find the cheapie units highly rated.

One needs to spend about $60 to get a decent power supply that's not going to be used by a gamer.