Ok, if you tried every A841 unit, then it should not be a control board (MM board) issue.
You can see the meanings for LED colors and error codes here
https://bitcointalk.org/index.php?topic=3224256You have tried installing a fresh new OpenWrt firmware.
You have tried different AUC3 5-pin cables.
What are the technical specs for your 5VDC wall wart psu connected to the controller?
Wallwart is one of those push-button Raspbery pi power cables:
http://a.co/iZMrojiThe LED colors on the miner, being green, seem to indicate a normal power up. AUC3 green is "normal". So I don't think there's anything useful in the LEDs.
No errors in the system, kernel or API logs. In fact, the API log just records the pool transactions. There seems to be absolutely nothing from the miners.
On the CGIMiner status page no devices show up - just the pool information.
All the controller information pages looks for all the world like it does when the miners are powered off.
Hope this helps...