Leave power supply plugged or unplugged when working in your computer?

[Ad Hominem]

Title. I know that most manuals that come with hardware will tell you to turn the PSU off and unplug it when working inside of your computer. I assume this is so you don't accidentally get shocked (even though you probably couldn't feel a live 12 volt rail even if you were dripping wet), or so you don't accidentally create a short to other components through your body and fry them. I'm more curious about what would happen with static.

If you did happen to have a static charge on your body and you touch the case before you put hands on a component, you would discharge that static to the case. But with the power supply unplugged, there is nowhere for that static charge to go. Hopefully your components would be insulated well enough from the chassis at ground potential, but that still seems like a bad thing to me to let loose a large change in potential like that.

I'm thinking if you were to leave the PSU switched off but still plugged into the wall, that would allow a ground path for that static charge to go away, since the switch (I'm assuming) most likely only breaks the hot line coming into your power supply from the wall, and the neutral path and ground path would still be intact.

[Malygos]

People make it a waaaaaaay bigger deal than it is I'm a licensed electrician have been for almost 10 years I've worked on my PC plugged and unplugged just depends on convienece hell I even tinker around while it's on and my whole house is carpet.

Touch the metal of your case before you mess with anything and you'll be fine

[Ad Hominem]

jefedemuchanina původně napsal:

People make it a waaaaaaay bigger deal than it is I'm a licensed electrician have been for almost 10 years I've worked on my PC plugged and unplugged just depends on convienece hell I even tinker around while it's on and my whole house is carpet.

Touch the metal of your case before you mess with anything and you'll be fine

Yea I tend to agree about that. But that being said, even I get a little skiddish when I'm installing like $1500 worth of PC hardware, I take the extra steps even though they're probably unnecessary. I actually broke my Titan Xp when it was like 4 months old and it was one of the worst feelings ever. But that wasnt ESD, I was trying to install an AIO water cooler on it using one of those Kraken brackets but I didn't have any 4mm hex heads to take it apart so I used the smallest adjustable wrench I had (which was still way too big). I broke a component off the PCB and scratched a trace in a different area. RIP. Only the good die young.

[Monk]

_I_ původně napsal:

esd bracelet is pointless if nothing you are working on is using earth ground

only components designed back in the 1970-mid 1990s were static sensitivie

This, so much this, static hasn't really been a risk to electronics for decades now, hell, my father ran a business selling cash registers etc for over 30 years, he employed 20 odd people, not once did I see them using anti static bands etc and to my knowledge, as I have asked, they never fragged a component through static and that's covering tens of thousands of circuit boards and components.

However, when it comes to psu's, depending what it I'm doing, I'll usually unplug it, discharge it and leave it a few minutes to dissipate charge before messing with stuff as frankly, a psu can mess up your day if it was faulty, same goes for pretty much any large piece of electronic equipment.

Now, in a pc, that's highly unlikely, but, it's a habbit left over from years past taking tv's, microwaves, psu's etc apart.

[hawkeye]

arstechnica.com/civis/viewtopic.php?t=732589

[Ad Hominem]

Monk původně napsal:

Now, in a pc, that's highly unlikely, but, it's a habbit left over from years past taking tv's, microwaves, psu's etc apart.

The caps in especially older TVs can put you in the dirt too, they're no joke.

[_I_]

yes, but the high voltage caps in a pc are in the psu and its outputs are regulated and most are disabled when the turn on signal is not grounded
only one thats active is the +5v vsb
and on a good psu with working protections will not turn on at all without proper input power

[iceman1980]

ESD Damage cannot be seen or noticed. As little as 10V of ESD can damage components not necessary destroy them but definitely damage them. Anyone that tells you ESD can't cause damage are a fool. And depending on the PSU the power delivery on that 12V Rail can be on the order of 134Amps.

High Current / High performance PSUs are not joke don't mess with them.

[Ad Hominem]

Product ∏ původně napsal:

ESD Damage cannot be seen or noticed. As little as 10V of ESD can damage components not necessary destroy them but definitely damage them. Anyone that tells you ESD can't cause damage are a fool.

ESD def can cause damage but most things these days are made in such a way that it is much less likely. Just dont touch the pins or contact pads and you wont tough anything that's electrically connected to a component.

[_I_]

its not the voltage its the current

if the devices you are working with are not grounded, there is 0 current

[Ad Hominem]

idk a static shock can be upward of tens of thousands of volts but at very low currents. I'm thinking it is the voltage that kills PC parts. its current that kills people

[iceman1980]

Ad Hominem původně napsal:

Product ∏ původně napsal:

ESD Damage cannot be seen or noticed. As little as 10V of ESD can damage components not necessary destroy them but definitely damage them. Anyone that tells you ESD can't cause damage are a fool.

ESD def can cause damage but most things these days are made in such a way that it is much less likely. Just dont touch the pins or contact pads and you wont tough anything that's electrically connected to a component.

That depends on the component. Very sensitive components such as DRAM controllers, the PCI-E PHY bridge and other highly sensitivity components do not like ESD if it is VLSI / ULSI (Very high scale integration / Ultra high scale intergration) they do not tolerate ESD well at all. ESD can literally knock the silicon doping out of wack,

Current and voltage are linked. Higher voltage, higher current simple law. Wet fingers would probably trip the OCP of a PSU.

[Ad Hominem]

Product ∏ původně napsal:

That depends on the component. Very sensitive components such as DRAM controllers, the PCI-E PHY bridge and other highly sensitivity components do not like ESD if it is VLSI / ULSI (Very high scale integration / Ultra high scale intergration) they do not tolerate ESD well at all. ESD can literally knock the silicon doping out of wack,

right, but GPUs and DRAM usually have shrouds and coverings on everything but the contact pads. the rest of the pcb has traces under a layer. I guess laptop ram doesnt have a shroud

[iceman1980]

Ad Hominem původně napsal:

Product ∏ původně napsal:

That depends on the component. Very sensitive components such as DRAM controllers, the PCI-E PHY bridge and other highly sensitivity components do not like ESD if it is VLSI / ULSI (Very high scale integration / Ultra high scale intergration) they do not tolerate ESD well at all. ESD can literally knock the silicon doping out of wack,

right, but GPUs and DRAM usually have shrouds and coverings on everything but the contact pads. the rest of the pcb has traces under a layer. I guess laptop ram doesnt have a shroud

I wear an ESD strap personally if I am working on soldering or working on my computer I leave it plugged it but switch the PSU back switch off.

Here is a very good explanation of ESD damage.
https://www.electronics-notes.com/articles/constructional_techniques/electrostatic-discharge/esd-effects-how-affects-electronics.php

[Ad Hominem]

Product ∏ původně napsal:

Ad Hominem původně napsal:

right, but GPUs and DRAM usually have shrouds and coverings on everything but the contact pads. the rest of the pcb has traces under a layer. I guess laptop ram doesnt have a shroud

I wear an ESD strap personally if I am working on soldering or working on my computer I leave it plugged it but switch the PSU back switch off.

I do too, for me it's because ESD wraps are cheap and PC parts are expensive. If I'm wrong about how easily things can get killed by shock and dont use the bracelet then I lose a lot of money from parts dying, but if I'm right and parts are more resistant to shock then I only lose 5 dollars for the bracelet. I'm just hedging my bets with risk vs reward or like a cost analysis.

[iceman1980]

Ad Hominem původně napsal:

Product ∏ původně napsal:

I wear an ESD strap personally if I am working on soldering or working on my computer I leave it plugged it but switch the PSU back switch off.

I do too, for me it's because ESD wraps are cheap and PC parts are expensive. If I'm wrong about how easily things can get killed by shock then I lose a lot of money from parts dying, but if I'm right and parts are more resistant to shock then I only lose 5 dollars for the bracelet. I'm just hedging my bets with risk vs reward or like a cost analysis.

I've also got a massive grounding mat and ESD tools. In a data centre you'd be advised to use ESD grounding points on equipment. Racks / Servers have grounding nodes next to them for you to wack your ESD clip on. networking gear can be a particular problem with ESD unless they're already shielded. Or STP cables.


PSUs are and can be a health hazard and as such you should observe proper work safety practices just like you would at actual work. Shortcuts lead to damaged equipment and injury. Is there a benefit to this caution? most definitely and not just with PCs.