The kind in the 90s with a giant CRT monitors and noisy hard disks & fans. I think "buzz" and "hum" are not loud enough because nowadays laptops still hum when overheated. But I don't know a stronger word. Thanks for any help!
Learn English – How to describe the sound of an old computer
word-request
Best Answer
You might consider whir, which Collins defines as:
Another possibility is drone. The word drone has many meanings, but it can be used as a noun or a verb to describe the noises you mention. From Wordnik:
As a side note, I'm not sure I agree that buzz is "not loud enough," because buzzing covers a wide spectrum of noises, some of them rather loud: