Rtb1Mine was DoA too (couldn't read microSD cards), and trying to communicate with HIFIMAN customer service is an experience that can best be described as "pulling teeth".
I mean, they suggested I flash the firmware (which requires me to put the firmware on a microSD card), when the problem was the player not reading microSD cards. Real helpful, HIFIMAN. Besides, the player was already on the latest firmware. FML.