I have recently received my Super Classic Mox (A-G-E) with SDIO WiFi card.
MOX booted for the first time, but later on I had problems to boot. Typically it was hanging in a state where the LED is just turned on. So I decided to flash it from USB but again no luck.
I have used the UART cable to see that there are problems with accessing the SD card:
mmc1: error -110 whilst initialising SD card
It indeed helped to eject and insert the SD card back, but still the MOX booted in 1 case out of 20.
Finaly I have removed the SDIO WiFi card and suddenly the MOX started to work as expected. No issues with start and no issues with flashing from USB.
I was surprised to see, that one of the connectors used by SDIO card is soldered to the USB port and connected by extra wire to one of the chips as pictured below:
Have anyone else seen something like this in his MOX with SDIO WiFi card?