Question Was having a laptop CPU problem this morning...

[ZedClampet]

Was like it was running on about 15% power. Temp was at 30 degrees. Checked all the power settings, and they were fine. Rebooted and it was the same. Ran a benchmark on the CPU and it was horrible. Tested whether it did better unplugged, but it didn't change anything. Rebooted again, and everything was back to normal. *wipes sweat off forehead*

Do you think this was a software issue since the reboot fixed it and since it had the same problem on battery? I really don't need a hardware issue on this laptop right now, although I don't think a new power supply would be very expensive. But I'm not overly comfortable working on laptops. They seem to be made specifically to discourage you from doing work yourself.

 

[Brian Boru]

I'm not overly comfortable working on laptops

I've only worked on a few, and always watched a YT video of a guy dismantling and reassembling each time, which helped a lot—there are always a couple of extra screws to undo, and a cable or two to be extra careful with.

Usually once you get the battery out and keyboard off, it's straightforward enough. First thing I'd check in yours is dust accumulation, altho your good temps don't point towards that. Maybe the CPU fan is clogged or failing, and the laptop was protecting itself.

I don't think a new power supply would be very expensive

Can you even replace the PSU? Never had to mess with that.

How old is the laptop, what model, which Windows?

This happened on first boot right, not after running some power-hungry app?

Do you think this was a software issue since the reboot fixed it and since it had the same problem on battery?

It could still be hardware, eg some part not heating up properly at first, some connection in a dodgy state. Clean what you can, and disconnect and reseat whatever you can—connections, cables, drives, RAM…

I don't know enough to advise, but I doubt a software issue would cause that symptom. You could run…
sfc /scannow [space before /]
…in a CMD window to check system files.

With luck, it's one of those inexplicable burps which happen from time to time, and are cured by the great savior of rebooting

You'll probably get better—more authoritative—answers in a while.

 

[ZedClampet]

First thing I'd check in yours is dust accumulation, altho your good temps don't point towards that. Maybe the CPU fan is clogged or failing, and the laptop was protecting itself.

I'm very good at cleaning it out once a month, so I don't think it's dust, and the CPU fan was functioning well. I was changing the fan speed while trying to figure out what was wrong.

I think that for some reason it didn't recognize that it was plugged in, and so it wasn't giving the CPU full power.

At this point I'm just going to assume it was a one-off. I've had problems with power cords before, and this feels kind of like that. But I was very sleepy this morning and didn't really investigate too much before the problem fixed itself. It could even have had something to do with the sleep settings not registering correctly since I had just wakened it.

Thanks for helping.