LMS6002D PLL is not loking

hi,
I am working on MYRIAD-RF1 board(LMS6002D). I want to lock the TX frequency to 416.8MHz. So after power on i am updating the TX PLL registers(0x10,0x11,0x12,0x13) with approriate values. But the output is not coming. Can anybody help me to solve this issue.
Thanks
NSN