Cross posting my post from another recent thread where the flashing blue front LED is being discussed. The following link deals with the second generation (v2.x firmware) single bay My Cloud and the two methods used to attempt to unbrick it and restore the firmware to it.
If you don’t know which single bay My Cloud version you have, check the P/N number on the bottom of the enclosure. P/N ending with -00 indicates first generation v3.x/v4.x single bay My Cloud units. These units have a slightly different unbricking process than the second gen units. P/N ending with -10 indicates second generation v2.x single bay My Cloud units. The link above deals with the second generation units.
