My 2008 Nissan Altima c.d. player keeps saying Read focus error. I have read that it might be possible to reboot the computer software by disconnecting the battery and it might clear up the problem. Do you think so? Also, if this has to get fixed at the dealership, do you know how much laser light replacement costs?

try cleaning it with one of the dvd cleaners may have dirty heads

check the format needed by the cd unit to read the cd's.

most common cause is a dirty or bad optical pickup in the unit, it may be able to be cleaned but more common is the pickup is bad.

Optical pickup inside which reads the disc is likely dirty or bad.

It can't read disc, try another disc preferably factory bought recorded disc not computer MP3 version off computer

There is a major difference between the way a DVD is formatted and used and the way a CD is formatted and used. For that matter there is a major difference in the way these are manufactured. There is nothing wrong with your CD player. Try burning your disk to CD-R media and make sure you close the sessions instead of DVD-r media.

optics are/have failed
you will need to replace the CD player

The laser light is out of focus and that is why it will not play cd's you might have to replace are take to the dealer to fix that problem they have the proper tools

MACHENIC

2005??? dealer only encrypted software so a plug in scanner will read the wrong code .From description try changing the coil pack