Start up my cloud 2TB

hi, my device mycloud does not start up.
Did reset with 4 sec, 40 sec without power/ with power.
Yellow led blinks, then comes continue and after 3 mins led is off.
Alsono communication with modem.

First, do you have a My Cloud or My Cloud Home? If you have a My Cloud what are the LEDs on the rear doing, if anything? You should have it connected to your router.