Wow! It means if your PSU is dead , you must ask directly the ASIC compagnies for a spare or upgraded PSU according to your miner?
If it yes how resellers deal with it in this case ?
I think there is a misunderstanding here, the control board reads the general model of the PSU not something like a special serial number, in other words, you can use any PSU from a different miner as long as they are the same exact model, so for resellers, they have APW9+ for example, it will work on all miners that have that PSU model, the control board will real APW9+, check the voltage and some other parameters and it will work just fine.
The problem is, it's hard to source these PSUs in the first place.
I ordered a 13000 usd L7+ and it is due nov 1-30.
I am already looking for a spare psi.