I have the AX1200i, not the HX1000i
According to your link,
According to the AXi series manual (AX1200i, AX860i, and AX760i),
Basically, for the AXi series (the models previously referenced), if doing a self-test shows a red light or no lights at all will indicate a faulty PSU
Your link contains other relevant information about the AX860i. I believe, based on my experience and many user reports, this information also applies to the AX1200i
Exact same problem I'm having
Again, exactly the same. Unfortunately, my PSU is being used in a computer running Linux and Corsair doesn't let you set a custom fan profile in Linux. I tried hooking the PSU up to my Windows PC to set a custom fan profile, which worked and fixed the problem. Unfortunately, Corsair doesn't save your settings to the PSU, so once you remove the PSU from the Windows PC, your settings are lost
Corsair knows this is a faulty design but continues to sell these units, in bad faith, without informing potential buyers