HI I just got the same diagnosis OPU test failed error code WCD43-013
when I put a dvd it burns it fine but it seems to not recognize anything i put in?
does it really needs to be replaced?
OK, I wasn't sure but now it's even more confusing.
I didn't want to give up on my optical drive so I did a recovery of my C hard drive after my system showed me a corrupted hard drive which I fixed and installed a malware software for free .
It detected 10 Problems and fixed it .
Then I ran a system check to see if I had a problem elsewhere no major problem was detected but I optimized my drives and defragmented them .
My optical drive works properly now. I ram the dell diagnostic and it passed all the test.
So make sure before you buy new hardware you don't have a malware or some virus which can messed up with the system and don't recognize your hardware and diagnose it with OPU test FAILED for optical drive.