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Zap from PSU

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September 13, 2012 1:55:22 AM

I went into my computer to change the top fan, and by accident I touched the yellow part of the 8 pin connector and it gave me a zap or a shock. I have always heard that when that happens, it usually kills your system in a way. I have since, turned on the computer and done a couple of benchmarks, to check if I damaged the PSU, or any other component. Everything seems to be fine, but do you guys think I should worry about anything?

BTW, Sorry I posted it in this section, this part gets more traffic.

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a c 78 à CPUs
September 13, 2012 3:08:00 AM

You are fine.
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a c 190 à CPUs
September 13, 2012 3:16:06 AM

new power supply dont power off when you shut the system down..they leave a little 5v line running. you may have gotten small 5v gingle or a zap from the ps caps. trick with working on a pc or laptop is shut it down then pull the power from it and wait 5 min for the caps to drain. your lucky there was no damage and it was low voltage. i seen people hit from crt tubes...not fun..
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a c 117 à CPUs
September 13, 2012 4:02:08 AM

smorizio said:
new power supply dont power off when you shut the system down..they leave a little 5v line running. you may have gotten small 5v gingle or a zap from the ps caps.

To feel anything through normal skin, you need at least 25-30V. At 5V, you won't feel anything unless you poke needles through your skin to use as electrodes or scrape it to make it swell and become more sensitive. 5V can barely be felt on the tongue.

Since the OP said he got 'zapped' while touching the "yellow 8-pin connector" (which means either PCIe or EPS12V) and dry air has a breakdown voltage of 1kV/mm, the discharge definitely is not anything from the PSU, it was static.

Luckily for the OP, power rails have beefy distributed decoupling capacitor banks all over the motherboard/cards/devices so ESD discharging to 3.3/5/12V or GND pins near power connectors is completely inconsequential. A 200pF 3kV ESD source discharging into a 12V plane with 7 500uF of distributed capacitance would charge to 0.3V not counting energy losses in the ESD arc itself nor the HBM's 1500 ohms body resistance, which is not threatening for anything regardless of polarity.
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September 14, 2012 2:36:35 AM

InvalidError said:
To feel anything through normal skin, you need at least 25-30V. At 5V, you won't feel anything unless you poke needles through your skin to use as electrodes or scrape it to make it swell and become more sensitive. 5V can barely be felt on the tongue.

Since the OP said he got 'zapped' while touching the "yellow 8-pin connector" (which means either PCIe or EPS12V) and dry air has a breakdown voltage of 1kV/mm, the discharge definitely is not anything from the PSU, it was static.

Luckily for the OP, power rails have beefy distributed decoupling capacitor banks all over the motherboard/cards/devices so ESD discharging to 3.3/5/12V or GND pins near power connectors is completely inconsequential. A 200pF 3kV ESD source discharging into a 12V plane with 7 500uF of distributed capacitance would charge to 0.3V not counting energy losses in the ESD arc itself nor the HBM's 1500 ohms body resistance, which is not threatening for anything regardless of polarity.

This has so much information, thank you.
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September 14, 2012 2:39:25 AM

Best answer selected by Lunixed.
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a b à CPUs
September 14, 2012 2:39:49 AM

In other words; if you actually got "zapped" by a power supply; you wouldn't be online would you now?
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