Xprotolab hardware V1.8, running v2.00. Device appears to be operating properly, including all four buttons. Holding the left button while plugging in the USB cable prevents the unit from booting normally, but neither of the LEDs light up and it does not appear from the computer's perspective. What am I doing wrong?

During normal operation, can the device connect thru the USB to the computer?

Issue resolved by using a different USB cable.
I had assumed that the Xprotolab would not appear as a USB peripheral until it entered boot loader mode. Using the first cable it would not enter boot loader mode when I powered it up with K1 pressed, regardless of the power source. I did not realize the?Xprotolab would not enter boot loader mode unless it was connected to the computer.