I just got a second hand Apollo BTC 'standard' unit, with apollo power supply.   It powered up fine, I see the red blinking lights... I have the usb attached to a raspberry pi running ubuntu 20.04 64bit, and I have the latest apollo-miner binary.   I just get this repeatedly, until it gives up:
>>> Waiting for USB /dev/ttyACM0 [1] !!!
>>> Waiting for USB /dev/ttyACM0 [2] !!!
>>> Waiting for USB /dev/ttyACM0 [3] !!!
>>> Waiting for USB /dev/ttyACM0 [4] !!!
>>> Waiting for USB /dev/ttyACM0 [5] !!!
>>> Waiting for USB /dev/ttyACM0 [6] !!!
>>> Waiting for USB /dev/ttyACM0 [7] !!!
>>> Waiting for USB /dev/ttyACM0 [8] !!!
>>> Waiting for USB /dev/ttyACM0 [9] !!!
>>> Waiting for USB /dev/ttyACM0 [10] !!!
>>> Waiting for USB /dev/ttyACM0 [11] !!!
>>> Waiting for USB /dev/ttyACM0 [12] !!!


I can see that ttyACM0 is the correct device...
[173260.253662] cdc_acm 1-1.2:1.0: ttyACM0: USB ACM device


any ideas? did I buy a bad unit somehow?