I have the same issue — I’m using a Pi 3 with an IQAudio Pi-Digiamp+. I used WinDiskImager on a pc and Pi Filler on a mac, on a previously used card and on a brand new card, always the green blinking light. I got the test file from IQaudio to work perfectly, sound played great. Also got NOOBS to load without any problems. Thanks for any advice.
