When they replaced my controller it took over a month. However, I sent them 3 dead hashboards on Dec 23rd. I had the replacements in my hands on Jan 6th. Problem is that one of the replacement cards died after 10 minutes. I can't see any reason for it to die -ie: heat sinks still in place and no burnt smell. So back to working on another RMA for the same batch 1 S7. My Batch 8s are 1 month old and seem fine so far..."knock on wood".