Power supply blew up

[manx87]

Hi guys, to make long story short, I'm building a new pc , i installed cpu and ram,mounted mobo into the case installed gfx card and drives and finally fitted psu which was the stock no-name psu labeled 400w which i think fake number,afer i check all connections and cables , i coonect the power cord to the socket and pressed the power button , nothing happened and just take a look inside the case i noticed the cpu fan spins for a second stops, so i disconnected pc and checked connections to make sure everything is ok, and at moment of stupidity , i changed the psu voltage switch from and powered on the computer again just to hear a loud bang followed by a smoke coming out of the psu I asap removed power cable from the socket and take out the psu which was smells like burnt wood, I checked the motherboard there is no visible damage that i can see , i'm now worried that any of my components get damaged , I ordered a new psu but hasn't arrived yet, please i need answer asap and i would be grateful,

thank you in advanced

my system specs
gigabyte ga-68a-dz-bz,intel core i3 3.ghz , graphic card is gigabyte gt240

 

[FinneousPJ]

Damn, don't use no-name PSUs. Hope your components aren't damaged...

 

[gamerk316]

And this is why you don't go cheap on the PSU.

 

[ukee1593]

Sounds like the PSU was fine ... Just don't be an idiot and set it to the wrong voltage.

If your supply is 240 v and you set it to 110 the PSU will be damaged and may also damage your parts.

I suggest that you check your motherboard standoffs. The problem you are mentioning is characteristic of the motherboard shorting out on the Motherboard tray due to no standoffs.

Check your household supply voltage before you start again.

 

[pjmelect]

If you change the voltage selector switch from 220 volts to 110 volts and you are on a 220 volt mains supply then the power supply blows up as you have found. What normally happens is that the varistors on the mains input go short circuit (permanently and there are two of them) and blows the internal fuse but the computer and the rest of the power supply are undamaged. If you have a particularly cheap power supply which does not have the varistors then the switching transistor and a lot of other components in the power supply get blown up, but fortunately this does not cause any damage to the rest of the computer. I repair lots of computers and I have seen this occur many times but it has never caused any damage to the rest of the computer. I think that you may have dodged the bullet here.

 

[RetiredChief]

Only way to tell is when you get your new PSU and try it.

Excluding the Input protection circuits as pjmelect mentioned and the voltage spikes.
If switching input 120 -> 240 (in US).
This would cause the AC output of the input transformer to be low (1/2). The regulator circuits would try to compensate, but can not. Output DC voltages should be low. The current for the regulator circuits would be over specs for the components, overheat and blow. The question here is when the PSU failed and before if expired, did it send any voltage spikes on the output DC rails.

If going from 240 -> 120 (ie England).
You have the opposite effect, the output from the Xformer would be very high, Regulator circuits again try but fail to regulate the DC outputs - which would be high and this could damage all computer components. Here instead of over current for the regulator circuits you have exceeded the voltage tolerence of the compentens in the PSU. Result is a much higher percentage of damage to external computer components.

Again only way to tell is cross fingers and try.
Please come back and let us know the outcome.

Added, as pjmelect mentioned, you did install the MB standoffs - right??

 

[beenthere]

As far as PSUs are concerned, be informed. Before you buy any PSU read accurate, objective PSU reviews at reputable sites such as www.jonnyguru.com or www.hardwaresecrets.com on the EXACT model PSU that you are interested in as some brands have good and poor quality PSUs.

You can also get an accurate rating of how much PSU power is required for your current or future system at the PSU calculator link below. Once you know the total PSU watts required then you need to confirm that the 12v rail has enough amps. to support your Vid card(s) and the rest of the PC system.

There are several websites that show the Vid card power consumption in watts. Divide the watts by 12 to determine the amps. required on the 12v rail(s). Add 15 amps for the rest of the PC on the 12v rail and you now know the Minimum total 12v rail amps required under full load. It's best to have at least 5-10 amps. reserve on the 12v rail available under full load so the PSU is not loaded to 100%.

It's also worth noting that people often misunderstand the 80% power rating. This is a rating of the PSU's energy efficiency not it's output. 80% plus PSUs use less grid power to produce the same PC power. If it's 80% Bronze, Silver or Gold the cost savings on electricity is pretty small between Bronze, Silver and Gold unless you are paying very high rates for electricity so any 80% rated quality PSU is fine even if not Gold. For those who leave their PC on 24/7 a quality 80% PSU is a good investment.


http://extreme.outervision.com/psucalculatorlite.jsp

http://www.guru3d.com/article/geforce-gtx-560-ti-sli-review/14

http://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_560_Ti/25.html