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I built my own computer and a year later the PSU (500W) burnt, I bought a new PSU again ( coolmaster 700W ) and now ( 5 months later) it is burned again. What could be the cause? Did I improperly wire my computer ? or is it the power outlet?

I checked the ground connectivity with my multimeter and it looks well grounded ( low resistance and 3V approximatively).

I have 2 hard-drive, a 460 GeForce graphics card. and a Quad core.

Thank you

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Can you be a bit more specific regarding the PSU, what model was it? What's the HDD brand and model, motherboard brand and model, and the amount of RAM modules? Also, any other hardware consuming from that PSU? – Zuul Aug 9 '12 at 19:20
Why? I listed all the necessary info, what would the model change? power is power, wether its modal A or B, 500W is 500W, no? – EEstud Aug 9 '12 at 19:37
Power is not only the 700W or the 500W, refer to Thermaltake Power Supply Calculator to get a clear picture of all the hardware involved for an appropriated power consumption calculation. And all that only gives you an educated guess :) – Zuul Aug 9 '12 at 19:42
up vote 3 down vote accepted

This could happen due to any of the following reasons:

  • The Voltage is unstable in your area (maybe you could use a UPS/Voltage regulator?)

  • Might be something with the wall outlet as you mentioned

  • The PSU cannot handle the load of all the components u have installed on ur PC. Refer to the specs of each component and focus on their power consumption then, estimate your overall wattage needs. Graphics cards and processors can get really demanding especially if you have some overclocking going on.

  • The PSU energy efficiency rating isn't that high? Or, perhaps it is a "no brand" that is not really delivering the wattage it promised you on the box (Edit: You mentioned cooler master so, I guess that's not a valid point).

  • Ventilation/air flow, space and cable management issues causing the PSU to overheat.

  • The power cable itself might be problematic if it's not high quality with proper diameter and other specs. I can recall, I had a similar problem when I purchased a cable that didn't come with the PSU.

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There's one that you've left off: "You've simply bought very poorly-made power supplies" (although Cooler Master generally aren't a problem...but generically it's an important point) – Shinrai Aug 9 '12 at 20:22
That's kinda embedded in my 4th point =). (Hint: no brand) – TjWallas Aug 9 '12 at 20:41
I guess I can read it that way, but IMO it's worth being explicit about. It doesn't have to be providing insufficient wattage (even as a percentage of what it's capable of, versus what is claimed) to fail as a result of shoddy components. – Shinrai Aug 9 '12 at 20:49

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