HL-DT-ST RW/DVD GCC-4244N [CD-ROM drive]

Hello,

I have an IBM Think Pad R 52 model with CD-ROM HL-DT-ST RW/DVD GCC-4244N [CD-ROM drive] Model. Recently It is not able to write to cds,but able to read cd and dvd.I have checked everything? Can any one suggest me how to solve this? One more question is How can we check the optical lens is working properly or not?

Thanks in Advance

Rskar