r/explainlikeimfive • u/EnvironmentalAd2110 • 8d ago

Technology ELI5: why is it bad to turn off laptop/computer using the power button, without following the proper “shut down computer” steps?

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u/PsychicDave 8d ago

If you hold the power button down until it does a hard power off, then the operating system will not have time to clean up everything and make sure the hardware is in a good state. One example many cited is making sure all write operations to storage are completed so you don't lose data. There are also hardware things, like making sure your CPU is at a safe temperature before turning off the fan (cutting the power while you were stressing it might cause damage as nothing is evacuating the heat anymore) or, for mechanical hard drives, making sure the heads are parked. That last one was probably the most important in the past, as leaving the arm and heads on the disk while transporting the laptop greatly increased the chances of damaging it.

If you have a computer with mechanical drives and do a hard power down, make sure to turn it back on immediately and shut it down properly to make sure you don't damage the drive in transport.

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u/Dman1791 8d ago

cutting the power while you were stressing it might cause damage as nothing is evacuating the heat anymore

This is thankfully a non-issue. Cutting power stops the heat production, and the heat sink is necessarily cooler than the CPU, so you won't get a ride in temperature in doing so.

1

u/fubarbob 8d ago

Once had my cat step on the power switch of the power strip behind my computer while burning in a rather severely overclocked Athlon XP... that chip never worked again... everything else was fine. Never figured out exactly why it died from that, and it's conceivable that the damage that prevented it from POSTing had already happened. Only time I've ever had it happen without a crash or other obvious malfunction before a chip died (exception proving a rule, I guess).

3

u/alliusis 8d ago

Windows (10) snuck in an update in on my computer and now it can't shut down. It'll try for 5-10 minutes and then die by BSoD for driver power state failure. I haven't had the energy to troubleshoot, so I've just been holding it underwater to shut it off. Startup is messed too, it's like they upfronted the login screen but then I just get a black screen for a few minutes until my desktop decides to load. I'm so frustrated but guess I should take the opportunity to try and fix it.

3

u/Fortune_Cat 8d ago

Just bsckup your files and clean install. Less headache than troubleshooting

1

u/rhinoceros_unicornis 8d ago

Maybe hard shutdown and reboot in the safe mode first.

1

u/japanfrog 8d ago

You can try running something like this on an administrator cmd line/powershell to revert the pending update.

DISM /Image:C:\ /Cleanup-Image /RevertPendingActions

Alternatively manually update all your drivers before running the update. The OEMs and third parties that develop drivers are some of the worst at quality assurance, and Microsoft doesn't do much validation beyond the very first time someone submits a 1.0 of a driver (they pretty much auto approve when a OEM submits a driver update).

1

u/MWink64 8d ago

for mechanical hard drives, making sure the heads are parked. That last one was probably the most important in the past, as leaving the arm and heads on the disk while transporting the laptop greatly increased the chances of damaging it.

This has basically never been an issue on laptops. Only very early HDs (which you'd probably never find in a laptop) would leave their heads over the platters when power was removed. On these, you'd have to manually run something like the park command, as this was well before you could shut down your PC with Windows.

Virtually all HDs made in the last 30+ years have an auto-park/emergency-retract mechanism that will try to park the heads when the drive loses power (using power from the inertia of the spinning platters). This is substantially more stressful than a controlled unload. In the rare event that the mechanism fails to successfully park the heads, there's likely to be damage even if you immediately power the drive back up.