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I've recently had some power issues with my PC and I thought it was due to the PSU being under voltage.

When I took it out my PC, I noticed it had quite the ammount of dust on it, so I cleaned it with compressed air then tested it with a voltmeter and it showed me it was delivering normal voltage (according to this graph : https://cdn.makezine.com/uploads/2014/04/da87333a_atx24-1bcq.jpg).

Since then (2 days), I didn't notice any power issues after cleaning & testing. I'm wondering if dust can affect the ammount of power a PSU can deliver. (Before testing, I had those power problems quite frequently.)

I did search on google but I could not find an answer, I'm just curious to see if dust was the problem.

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  • \$\begingroup\$ It's more likely that the main air intake filter to the PC case became clean when you dismantled it - it being partially blocked can shut-down CPU speed dramatically. \$\endgroup\$
    – Andy aka
    May 18, 2020 at 12:27

2 Answers 2

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2 main ways

  • Dust can be conductive, meaning it may cause the feedback network used for the controller to read the wrong value
  • The power supply may be entering some kind of thermal protection, where when too hot, it starts decreasing the maximum current, which causes the output voltage to start falling.
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  • \$\begingroup\$ thanks for the answer. According to you first point, this means that if my PSU is delivering 12V, dust can, in a way, false the reading of that value and display to the PC to 11V for example? \$\endgroup\$
    – Fire Frost
    May 18, 2020 at 12:15
  • \$\begingroup\$ yes, most controllers have a resistor divider, or a sense winding from a transformer to know what voltage is at the output, if the pin on the controller that is measuring that voltage is conducting to a power rail above it, the chip is fooled into thinking the output voltage is higher, and for you results in a lower output. \$\endgroup\$
    – Reroute
    May 18, 2020 at 12:18
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Excessive dust can limit the performance of the intake-fan and heatsinks. If the fan can't blow enough air or the heatsinks are covered with dust then the heatsinks may get warmer. And if your PSU's controller is smart enough then it can limit the output power due to the increased temperature read from the sensor(s) attached to the heatsink(s).

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