Hasn't been on in 6 months..wont accept discs?

If its a 6 disk cd system the cd tray is wedge causing the cd option to not work. Most of the time one of the cd slipped out of its position causing it to wedge

Usually no disc error is dirty or bad Optical Pickup in the unit itself.

Try replacing the battery...

It sounds like the optic sensor went bad. If this goes bad it wont be able to tell if a disc is loaded or not. So it can't accept or reject them.

You're in luck, you're still covered under warranty.

Call Sony @ 1-800-345-SONY and get it repaired for free.

Try to use CD/DVD clening disk ($6 in Walmart). Or simply use cotton swab (Q-TIP) and 40 % ethyl alcohol (vodka) or 50-70% isopropyl alcohol (NO ACETONE), depending on your budget.
Also check if discs are inserted correctly and not damaged/durty etc. Also check your discs. Some CD-players dont accept burned CDs (copyed). I believe Sony is not the case, just a suggestion.
If cleaning wont help lens might be damaged.
Good Luck

well you can get a cleaner wii thing cause your wii might have dust in it so you can try that there around $20-$30 each in aus so that should work

Compressed air can be fired straight into the Wii
call this number for troubleshooting call 1-800-255-3700 and talk to a live representative

man i too have a proble mm mine ps3 stopped reading ps3 disc but it reads only ps2 and other disc. but wont read ps3.. disc i tried getting a new one but it didnt work

If you have posted the correct model of writer, then it only supports the writing of DVD+R and DVD+RW discs, but CD-R and CD-RW disc writing are supported, and it should play all forms of DVD, so it won't burn DVD-R and RW discs, but if it wont play all types then try a cd/dvd cleaner, but to be honest when writers start playing up the lens is normally faulting and a replacement drive will be required.