GSA-4163B Won't read/write CD's

I hope I’m in the right place for this question. My daughter has a LG GSA-4163B drive which today has failed to see any CD’s. It works fine playing DVD’s but will not ‘see’ any CD’s whatsoever.
Maybe I need to post more info. so please, if you can help tell me what info. you would need to know?

Usually this means a problem with laser calibration. It sometimes happens with dvd writers: they can still burn dvd’s, but not cd’s and not even read them. If it is covered under guarantee, I suggest contacting the supplier or LG in your country to ask for a RMA.

Thanks for your reply. I will follow your advice. I replaced the drive today with a Plextor PX-740A (figured the LG was duff) as my girl needed to get stuff burnt for her pals, school starts Thursday.
Again, thanks for the advice.