650mb cdr not readable. Why?

arthur148 wrote:

Ink. Wikipedia has an article on it under CR-R

FWIW, I think you meant "dye" degradation. If the drive is broken your only real option is to purchase an external CD/DVD drive. MacSales is a good resource.

BTW, does your MacBook Pro have a built in CD/DVD drive or are you using an external? Either way the drive could be dirty and need cleaned or need repaired.

arthur148 wrote:

I have quite a few cdr's that aren't readable and are rejected by my MacBook Pro. On a PC I can pull up the directory. Yes they were made on a PC.

The one common factor in all of them is they are the older format of 650mb. There is apparently no ink degradation since the ink appears consistent.

Why?

CD-R (Compact Disc-Recordable) is a digital optical disc storage format

Ink degradation???

Try a commercial laser head cleaner. You can find them most anywhere

https://www.bestbuy.com/site/endust-laser-lens-cleaner-blue/5611319.p?skuId=5611 319&ref=212&loc=1&gclid=EAIaIQobChMIrfGkpr2G3QIVTrXACh2aHAYHEAQYASABEgLRS_D_BwE& gclsrc=aw.ds

There historically is always issues with cd/DVD made on PC vs Mac and the other way around.

Did you try running them on a Windows PC?

ink?

Often, Windows doesn’t close the session. If they don’t, macOS can’t read the open session.