My cd player says "no disc"...

SOURCE: `Sony CD player won't play burned discs

Many of the older Car CD Players will not play CD-R's or they may with static sounds behind the music. What you need to do is try using a different brand of cd-r disc. If this doesn't work then it means that you may need to replace the CD player because the model that you have may not be decoded in order to play CD-R, CD-RW, play MP3's or anything of that such.
Get back to me if this doesn't work I'll help you square it away.

SOURCE: CD Player doesn't work; says "disc"

i would say that your lense is dirty and yes cleaning it might help

SOURCE: CD player will cycle through all 5 discs and then show "No Disc"

HI. the main board is ok. this is the actions of a malfunctioning optical lens assembly. the lens is unable to read, due to the damage to its structure or, the laser has burned out.

The main board is programed to issue the (no disk) alert if the lens doesn't relay audio data. simply replacing the failed optical lens assembly will fix this issue.

SOURCE: NO Disc

The first step is to clean the lens of the player using a cotton swab and alcohol. If that failes to resolve the problem, it is likely that the optics are starting to fail and need to be replaced.

Please clean the lens and update this with the results.

Thanks,
Dan

SOURCE: cd player not reading discs.

The reader is not recognizing the disc which usually means there is a problem with the circuitry or the "eye" itself. It will probably cost you more to repair this unit then to purchase a new one. Especially since CD players have come way down in price.