My 20" iMac G5 2.1 Ghz (iSight) was always very quiet.
Now I notice a scratching noise from the lower middle right part when I start it up or when I launch an application.
I guess this is where the hard drive sits.
I have not noticed that noise so distinctly before.
It may be normal.
It may be not.
I just had the iMac repaired - a new SuperDrive put in.
I don't know if there is a connection.
What to you think?