This topic is getting full with questions about defective hardware 
As far as I know and experienced in the forum the failure rate of Avalon Miners is the lowest of all Manufacturers.
avalon 4.1
avalon 6
avalon 721
the august 741's and the minerwarez 741'sin sept seem to be a bit worse.
From 100 machine, I got 3 defective miner like I explained above and already send email to them and got no reply at all.
and
106 power supply, I got 8 defective (They said they are going to replace it, we'll see about that whether I will received the replacement or not, will update if I received replacement)
So I guess if they didn't replace my miner, then that's mean the Avalon miner cost, I have to add up 3% (defective rate)
Avalon 6 all good no defective, just the some miner hashrate is not like it was advertise (3.5 Th/s) but at least no defective.
we'll see about the new type later, hopefully its not as bad as 741 like Philip mentioned and what I received.