OK, the time line was not apparent from the original posting.
By "dead" do you mean as in literally no noises or residual torque at all, or just that it won't move?
And is the rest of the printer OK?
The auto homing implies that it is at least powering up.
But as I recall Y homes first, then X usually.
My printer is about 40 miles away at the moment so I can't check.
Most likely one of three things has happened (in increasing order of probability)-
* One or more motor wire connections have been broken or shorted
* The firmware is corrupted for some reason (hey, it does happen)
* The step stick (driver) is fried
Drivers can be fried for many reasons and are the weak links in the system.
And they have been known to simply fail with no obvious reason, or from overheating.
First double check the wiring for any pinches, shorts or separations and repair as needed.
Then try swapping the Y stick with the one from the Z motion and see if the motors move.
It doesn't matter if the current setting is wrong (for a few moments anyway), this is just to see if the original step stick is OK or not.
If that doesn't work, re-load the firmware to the board.
It is vanishingly unlikely that the motors are at fault.
It is also unlikely that the main board itself is at fault, but that is not unheard of.