Question Is switching the PSU off after shutdown safe ?

[ridwan123]

I am just wondering of that because i always switch off my psu after i shutdown my pc.PSU montech century g5 850w 80+gold

 

[rgd1101]

why?

 

[ridwan123]

why?

To ensure that no people touch my shining pc

 

[rgd1101]

and people don't know how to turn on the psu?

 

[JeffreyP55]

I am just wondering of that because i always switch off my psu after i shutdown my pc.PSU montech century g5 850w 80+gold

When it powers down the PS IS off. You are just removing the AC power source.

 

[--SID--]

The switch is not made for daily use and the daily inrush current can damage the NTC Thermistor even when you remove the AC.

 

[dev_cyberpunk]

When it powers down the PS IS off. You are just removing the AC power source.

It kills the standby and net power if wake on lan is enabled.
If the desktop was in certain remote desktop session, like google desktop, the connection stays connected until AC power is removed.

 

[JeffreyP55]

It kills the standby and net power if wake on lan is enabled.
If the desktop was in certain remote desktop session, like google desktop, the connection stays connected until AC power is removed.

I don't see any mention of such a condition with his setup. Looks pretty generic.

 

[ohio_buckeye]

You don’t want to do that. Your motherboard has a battery that helps with keeping your bios settings etc. Usually you want to keep the power supply on so that you can keep some residual power going to that battery.

Turn off the monitor instead?

 

[JayGau]

To ensure that no people touch my shining pc

You don't have a password to access your PC? I don't see how turning off the PSU prevents anyone to touch it. PSUs are not designed to be powered off like that every day. Just turn off the computer, leave the PSU on and set a password on your account if don't have one (it takes me 0.5 seconds to type my Windows pin). You can even set a master boot password in the BIOS if you want to prevent anyone to boot the computer.

 

[Gururu]

I agree with all. Don't do it. I think you will wear out capacitors which may stay charged while plugged in. Not sure if they drain when the pc is shut down normally, but draining and charging so often might wear them out.

 

[dev_cyberpunk]

It really makes no difference at all. Using the power switch after shutting down the OS is not going to harm it.

Btw the people who don't know, the bios battery is a continuous discharging circuit. So it doesn't matter if the board sits on a shelf or installed and running in a machine.

 

[ridwan123]

You don’t want to do that. Your motherboard has a battery that helps with keeping your bios settings etc. Usually you want to keep the power supply on so that you can keep some residual power going to that battery.

Turn off the monitor instead?

ALways turn off the monitor

 

[ridwan123]

You don't have a password to access your PC? I don't see how turning off the PSU prevents anyone to touch it. PSUs are not designed to be powered off like that every day. Just turn off the computer, leave the PSU on and set a password on your account if don't have one (it takes me 0.5 seconds to type my Windows pin). You can even set a master boot password in the BIOS if you want to prevent anyone to boot the computer.

I just dont want people turn on my computer even though they cannot access.sometimes people are fussing around

 

[Misgar]

Using the power switch after shutting down the OS is not going to harm it.

A friend came round with his computer because the power switch on his ATX PSU was making "fizzing" sounds and the PC was not powering up. It seems he toggles the switch three or four times a day and after 5 years of use, the switch had finally died. I told him to buy a new PSU.

When I opened up the faulty switch, the metal contacts inside had partially melted from repeated arcing and the plastic switch housing was charred. Typical switch on currents in ATX PSUs lie in the range 20A to 100A, even with an NTC thermistor.

https://www.tomshardware.com/reviews/asus-tuf-gaming-550w-bronze-power-supply-review/2

The small switches in ATX PSUs are typically rated at 10A or 16A AC (continuous current rating) but repeated surges of up to 100A can eventually wear out the contacts. I advised my friend not to toggle the switch all the time, but he continues to do so. He chose the cheapest replacement PSU available, so it could fail sooner rather than later.

If I left all my computers and servers connected to the mains and running in standby mode, the Vampire power consumed would probably exceed 200W. At the equivalent of US $0.33 per kWhr, I'm not prepared to waste money unnecessarily. The net result is I switch off my computers and monitors at the wall when I've finished using them for the day.

 

[Roland Of Gilead]

You don’t want to do that. Your motherboard has a battery that helps with keeping your bios settings etc. Usually you want to keep the power supply on so that you can keep some residual power going to that battery.

Turn off the monitor instead?

This^^

 

[dev_cyberpunk]

A friend came round with his computer because the power switch on his ATX PSU was making "fizzing" sounds and the PC was not powering up. It seems he toggles the switch three or four times a day and after 5 years of use, the switch had finally died. I told him to buy a new PSU.

When I opened up the faulty switch, the metal contacts inside had partially melted from repeated arcing and the plastic switch housing was charred. Typical switch on currents in ATX PSUs lie in the range 20A to 100A, even with an NTC thermistor.

https://www.tomshardware.com/reviews/asus-tuf-gaming-550w-bronze-power-supply-review/2

The small switches in ATX PSUs are typically rated at 10A or 16A AC (continuous current rating) but repeated surges of up to 100A can eventually wear out the contacts. I advised my friend not to toggle the switch all the time, but he continues to do so. He chose the cheapest replacement PSU available, so it could fail sooner rather than later.

If I left all my computers and servers connected to the mains and running in standby mode, the Vampire power consumed would probably exceed 200W. At the equivalent of US $0.33 per kWhr, I'm not prepared to waste money unnecessarily. The net result is I switch off my computers and monitors at the wall when I've finished using them for the day.

Sounds like Asus is making junk power supplies. Looking at what else they make and seeing issues with motherboards, I just stay away from them. They used to be ok, but asrock seems to make a better product now these days.

The inductive kick is normal in a switching power supply and if they used the correct power switch it wouldn't have failed.

 

[dev_cyberpunk]

This^^

is misinformation.
The only motherboards that have power going to the cmos battery are the industrial boards that have rechargeable batteries installed.

 

[Misgar]

The inductive kick is normal in a switching power supply and if they used the correct power switch it wouldn't have failed.

I think it's a "capacitive surge" and the resultant high current that degrades switch contacts when power is turned on due to arcing. The bulk capacitor in an ATX PSU starts at zero Volts, then charges rapidly up to 340V DC (from my local 240V AC supply). Hence the high surge current up to 100A.

Inductors may play a part in switch degradation when the PSU is switched off, releasing stored energy and causing arcing across switch contacts as they open.

I've had switches in cheap 13A mains sockets die after 2 years of switching ATX PSUs on an off, just like the switches in some ATX PSUs. The cheaper the switch, the sooner it's likely to fail.

I've also had to replace relays in remote control 13A mains switches after repeated on/off cycles with ATX PSUs. They last a few years, then the relay contacts fail.

Sounds like Asus is making junk power supplies.

It's not just Asus PSUs that have high inrush currents, especially when used in regions with a nominal 230V AC supply.

Here's a Seasonic 750W PSU:-
https://www.tomshardware.com/reviews/seasonic-connect-750w-power-supply/2

A Corsair 550W PSU:
https://www.tomshardware.com/reviews/corsair-tx550m-power-supply-review/2

A Thermaltake 1200W PSU:-
https://www.tomshardware.com/reviews/thermaltake-toughpower-gf3-1200w-atx-v30-power-supply-review/2

I've just noticed these PSUs from 3 different manufacturers all draw 86A peak at switch on when tested at 230V. I'm sure there are "better" PSUs with lower switch on surges and a few with even higher currents.

Looking at what else they make and seeing issues with motherboards, I just stay away from them. They used to be ok, but asrock seems to make a better product now these days.

I have a couple of Asus mobos, one with a 3800X (from 2018), the other with a 7950X (2022) and they're still working fine. I also have Gigabyte, Asrock, MSI, SuperMicro, Intel, Dell and HP motherboards. No absolute favourites.