I have a LimeSDR Mini V1.2 (purchased on 20 March 2019) that on initial arrival responded OK, and had its firmware/gateware upgraded to 6/1.29 (using LimeUtil on a Raspberry Pi) successfully.
On the next attempt at use, it failed to respond to USB. It is not listed in lsusb on a Raspberry Pi, and on Windows 10 it says “Device Descriptor Request Failed”. This is the same for USB2 or USB3 sockets on the PC, and the same computer responds properly to a working LimeSDR Mini.
Neither LimeUtil nor the LimeSDR_Mini EEPROM programmer can see the device (but they can both see a working LimeSDR Mini).
The on-board LED flashes red/green when it is plugged into a USB socket, the power supply rails seem normal and I cannot see any sign of mechanical damage. I can’t access the device serial number, but the sticker on the underside of the board is 3121476.
Do you have any other ideas, or is RMA the only option?