[Nottingham] Odd thing with DVDs

[Dave Luff]

On 26/03/13 17:56, Jason Irwin wrote:
> I've been noticing that about every second cover DVD from LXF isn't
> recognise (e.g. the latest one from LXF 170 does work).
>
> when I insert a working LXF disc (e.g. 169) I see this from "dmesg | tail":
> [20648.469260] ISO 9660 Extensions: Microsoft Joliet Level 3
> [20648.521012] ISO 9660 Extensions: RRIP_1991A
>
> And when I eject:
> [20684.406735] VFS: busy inodes on changed media or resized disk sr0
>
> All looks as-to-be-expected
>
> When I insert a non-working disc...nada.  And I know the disc works as
> I've tried it elsewhere.
>
> Where does one begin with diagnosing why the disc isn't getting picked up?
>
I normally begin by examining the surface for fingerprints, scratches etc.

I have successfully fixed a CD drive with similar symptoms to those you 
describe (intermittantly not reading when others would) by greasing the 
laser rail with silicone grease to remove stiction.  CD writers were 
more expensive back then though!

Your post indicates that you suspect a software rather than hardware 
issue though, in which case I have no idea!

Cheers - Dave