Phantom 2 won't take off

[AG80]

My first post on here after taking in all the great info shared on here. I've just spent ages checking everything and was hoping to have my first ever flight - but - My phantom 2 (with zenmuse and gopro) won't take off. The throttle causes all 4 props to spin, but it doesn't seem to have enough lift to take off. It looks if one of the props is spinning a bit slower than the others. Any help would be much appreciated. I am new to all of this but like others have done loads of reading and research but have little practical experience.

 

[750r]

Do you have your props on correctly (right derection) ?

 

[AG80]

Thanks yes, pretty sure I've done that right.