blowing out power supplies

Not open for further replies.
I keep blowing out power supplies. It happens usually with a loud snap or a fizzle and a snap. I can see a flash come from the power supply through my case window. It can happen once a week or twice in a day, hot day, cold day, within a minute of turning on or within twelve hours. I could be touching the keyboard or leaving the computer unused for hours. What I'm getting at, is it seems random. It's happened about twenty times. Expensive high output power supplies have to be replaced. Cheap 300 watt supplies might survive one or two events before replacement.

I've disconnected each of the two mirrored hard drives alternately and it still blows. I've disconnected the Fan speed contoller and the HP DVD RW. I've changed all of the seven fans.

The mirrored raid set flashes "incomplete" whenever I boot up. I've reset it once, but it came up incomplete within a few starts.

So, I think it's the Motherboard blowing out the power supplies....?

I have a Soyo Dragon 2 Motherboard
P4 2.4Ghz 800M 478P/512K HT RT and I haven't clocked it up.
Ti4200-VTD8X video card
two 80G Maxtor SATA HDrives in a Mirrored set.
DDR 2X256MB Ram
Sony Floppy

It's the first computer I've ever put together.
I may be slow, but I'm not dumb.
HHHeeeellllllp !!!?


Posts: 2,218   +0
Well, you have two possibilities. Either you have a problem with the mobo, or a problem in the power outlet, surge strip, or the line itself. Since you seem to have at least a few dead PSUs, you might take one to a technician and have him look at it and tell you what is blown, this could help you figure out whether it was blown by the line coming into the primary, or if it was an overload caused by a fault in the mobo.
Just from the description alone, I'd say it was power spikes or an intermittent dead short on the motherboard. Look to make sure nothing is in the case that could be periodically making contact on the mobo that might cause a short, also look to make sure nothing is wedged between the case and mobo.


Posts: 1,929   +15
1. Welcome to Techspot! :wave:

2. No need to double post (this is also in Other Hardware)

3. Nic and StormBringer have both said about the same thing, it sounds like its the circuit in your house, or your motherboard has a screw or something behind it.


Posts: 1,519   +1
So what exactly is your question?

Firstly, buy high quality PSU's that have a full suite of output protection (overvoltage, overcurrent and short-circuit protection) so that you don't need to keep replacing them.

Secondly, it sounds like you are getting an intermitant short-circuit to ground which is blowing your PSU. This is assuming that you aren't using defective PSUs, or cheap PSUs that are being maxed out supplying your system, until they finaly give up.

I don't think you are getting spikes from the mains circuit, as the fuse in your plug would have blown, and other equipment would also have suffered.

Some info on the PSU brands and current ratings would help. The mainboard seems a likely culprit at this stage, much as you said. When did this problem start? Was your system ever working fine, and if so, for how long?

Edit: I moved this post from its previous location. You should go back and delete the other thread.
I forgot to mention that I've used top dollar power supplies and cheap power supplies too...the cheap ones lasted MUCH longer, surviving three to five events where the top of the line PSUs died on the first event.

I've used power surge protectors. I've used power surge protectors protecting regulated battery back ups with power surge protectors built in. I've used the number one brand name top of the line UPS "clean power" device. ....It's not in the electrical supply.

So, I'll scrap that top of the line Soyo Dragon 2 Motherboard that everyone gave such bright reviews. The second best rated Motherboard was the ASUS.

This is my first attempt at building and I don't want such a bad experience. I've carefully chosen the parts after a lot of research and design, and still I feel like I'm screwed. If changing the motherboard doesn't stop it, what next?


Posts: 2,218   +0
All you needed to say was that you'd used a line conditioner, that would have served as evidence to me that it is not the line voltage.

Since it seems to be the board, I would suspect a foreign object is the culprit. A large percent of such problems I see are caused by a screw or washer wedged behind the mobo, or that the mobo was not properly mounted. There is a chance it could be a factory defect in the board.


Posts: 1,519   +1
How about telling us the model/brand of some of the PSUs you've tried?

Also, as StormBringer mentioned, the issue could be caused by some stray metal component shorting your system out. Maybe you should strip your system down, and rebuild from scratch. Make sure you dont have board stand-offs fitted in positions that dont have mounting holes on your mainboard. Do all your other components still work?
I've used four or five Antec 480w true power.
I've used three Enermax around 500w
I've used a Super Tornado 300w
I've used ATX 300w (this is the most durable and cheapest).
And a couple other cheapies..

I assembeld the Motherboard to the case three times originally, just for practice. Re-reading the instructions each time for memorization.

When the second power supply blew after a few weeks of successful use, I removed the Motherboard and looked it over for sloppy fittings, splattered solder, bad connections, foreign objects etc.

I'm going to try Soyo Customer Service today and see what they think when I tell them all about my configuration of components. I'd rather buy a second Soyo Board and then send in my current board for warranty, so I can keep using my computer. I work constantly with this computer and can't afford to switch to my lap top and then have to transfer files afterward....and put off work with programs that exist only on this computer.

This Soyo board does everything that I currently do with my computer and will expand to do everything that I want to expand to over time. It's still bragged about and raved over by more people than any other MB on the market. I had intended to build a couple more computers with similar but faster configurations.

You guys have definitely helped and I want you to know, "I appreciate it." I'm going to need to know more about "Raid" configurations in the near future.

Frank Smith

Posts: 75   +0
Last thing to try replace all metal screws with nylon and use fiber washers.
Never had a student blow due to shorting problems... when instructing on how to build a computer... also too long is worse than too short.
After dozens and dozens of Power quit...

I took the super computer home to my sailboat three or four times, for weeks and even months at a time. The power supply NEVER blew out at home. Not once. Every time I took it back to work, it's blow or produce it's tell tale "snap!" within a day or so, and after one or two snaps, it'd blow again.

Eventually, we have a lightning strike onto a transformer just outside my shop along the street. Big explosion and power was out until the transformer and some cables were replaced. After that, the power supply NEVER blew or snapped again.

There are a couple other computers in my building and three more in another building that was effected by the lightning strike. None of those computers ever had a power problem. I have had other computers in my building and laptops pluged into the same outlets, never having had a problem.

No one has ever figured out why just that one computer.
Not open for further replies.