Awesome, good to know!
HP Procurve switches have a lifetime warranty. I’ve replaced several over the years, even if one port failed. The only time it was denied was when I told them the fan was very noisy.
“Does it still switch?”
“yes”
“We only replace it when it fails to perform”
Fortunately it was in a closet, so it didn’t really bother anyone, and AFAIK it’s still working fine.
I would imagine that if you took the lid off and replaced the fan, the warranty would be voided. 
Netgear Pro (lifetime warranty). We told them one of the fans had failed and they authorised the replacement. From our point of view, it had already ‘failed’, and I didn’t need to explain that by ‘failed’ I meant that it was making a screaching noise.
When I was doing mechanical engineering work, we considered that ‘failed’. Of course, in that job, if the line stopped, 40 people were standing there getting paid to do nothing, while the income had stopped too. Kind of like the network in a big company.
[Original Poster]: 10 years ago, you might have had to think about what you plugged into which hole. It’s all autosense now.
Cool!