Hi
This is an AP9331(the cpu of 703n) bug. I have document it here:(Why there is a USB-HUB inside )
https://en.bitcoin.it/wiki/Avalon#FAQ more info here:
https://forum.openwrt.org/viewtopic.php?id=39956But it not happen on all 703n. if the Avalon have this issue.(this should be test before Avalon ship out) people can try those:
1. Try different 703n. you can easy to buy them. and it's very cheap.
2. Add another usb-hub inside. <--
ONLY For Fpga controller
1.5 3. Replace 703n with other device. like RaspberryPi. cheap PC. then you have to handle the cgminer/monitor etc.
4. Replace your fpga controller also
MAY fix that.
Cherish your life, stay away from mining.
Xiangfu
So I recabled my Avalon but I don't have a connector for the "EPS_12V_2" since this PSU has only one "CPU cable".. so i left EPS_12V_2 empty...
I plan to do some maintenance on my farm later, so I can check then, but I distinctly recall EPS_12V_2 not being connected on my Avalons.
The errors you mention:
[ 3304.340000] ftdi_sio ttyUSB0: failed to get modem status: -71
[ 3304.340000] usb 1-1: clear tt 1 (8030) error -71
Those are the same errors one of my Avalons was spitting out. I narrowed it down to a bad TP-Link. I have that unit running off a RaspberryPi with no issues now.
So, I would suggest plugging your Avalon into a PC and running cgminer on there, to test and see if your TP-Link is busted like mine seemed to be.