I have the same issue as stated above.
RPI 3 Model B v1.2
SD Card: Kingston 8Gb
Flashing software: Etcher
Board: Hifiberry Amp2 1.0
Boots without a hiccup without the board
When I plug the board: Gets stuck at Time Synchro. Stops it once. Retries and freezes after 24sec out of 30.
I tried with an RJ45 cable (Ethernet) plugged in and without.
Both the Raspberry, the flash card and the Hifiberry board are brand new.
Any suggestion? I’d love for my multiroom audio system to work 🙂