2 props don't spin up.

[FTL900]

I have a Mavic Pro Platinum, and it worked great last time I flew it and put it away.
Now the rear 2 props spin up, but the front 2 props don't move. Any suggestions? Has anyone seen this before?
It has not been updated or anything else changed since it flew last. It has not been crashed or dropped.

 

[old man mavic]

how long was it laid up for and where, do the motors turn by hand take the props off and check to see if anything is obstructing them

 

[MTW4518]

Is the area you are testing from level? If there is a angle to the area the lowest props spin up first

 

[AnzacJack]

Is the area you are testing from level? If there is a angle to the area the lowest props spin up first

And then how long does it take for the other props to spin up?

 

[MTW4518]

Should be right when the craft lifts its low side off the ground and becomes level. I would try to take off from a level area and if the props dont spin up all at once, then you may have an issue