Some Nano's work, some dont'

[berzerkr]

I've ordered a bunch of Avalon 2 Nano's. I'm using a Raspberry Pi. I have a powered USB hub that they are connected to . Some of them work right away , some don't. They all say revision 2. All are supposed to be brand new from vendors on Amazon. I can't see any difference other than if they work they do and if they don't (the first time i launch cgminer) then they will not. I've tried different slots, different combinations etc. always the same avalon nano's either do or don't work. Luckily i got a bach of three that work perfectly and have been running for a week straight but i've ordered about 24 and most of them don't. I came here hoping to find that the ones that don't work just needed a firmware update, but then i see the post about having a special board to do the firmware update. I get the same results with bfgminer. I do not , nor do i intend to , use Windows. Side note: I used the build of cgminer from the canaan-creative website and i'm including the speed settings in the command line for cgminer. Obviously it's right to a certain degree because that batch of 3 work and miner perfectly. The LED is red on the 3 that always work no matter what USB slot they're attached to . Any advise on what is going on? thanks in advance.

[qinfengling]

@berzerkr Please check the hardware version with the wiki https://en.bitcoin.it/wiki/Avalon_nano#Hardware_version_1.0, you can check VID and PID by lsusb on Raspberry Pi.

[berzerkr]

Update: The Nano's that don't work under cgminer also don't show up in lsusb.. out of the 11 i've received so far only 3 work. Could it be that they're all defective? LOL