I have 4 of the 10.3 models they are just crappy machines. The boards are probably dead. I am somewhat knowledgeable and have never been able to fix them. I ran into pretty much the same issue you are describing.

Innosilicon helped me fix my issue they were very responsive and helpful and it was even dureing there holiday weekend. I have a funny feeling that INNOSILICON is gone for good at least in the USA. With the ban they probably dont want the risk of selling machines directly especially to the US.

You can acess there website useing a VPN from china it looks almost the same as the US site but there is no mention of them producing and Mineing related items. That whole section is gone

I am new here but had to join to say that you guys are not alone, i received several T3 Units earlier this week and every single one is locked as well. I basically got a bunch of really expensive heaters. I wonder if this problem is just limited to the few of us? Because they sold our of the machines on there website fairly quickly so you would think many people would have this issue? I have searched everywhere and have not found many people complaining of this problem or any valid solution other then begging them to fix the issue

I also emailed Innosilicon but i understand they are on a holiday, So hopefully they respond Monday. I am not very confident because my past experiences is they NEVER return emails ever. If they get back to any of yous can you please let me know what the solution or explanation is for this? I don't understand how this can happen other then it was intentional?