Silver disc are DVD and blue disc are CD-ROM. Older ps2s dvd laser would go
bad and would stop playing silver disc and dvd movies. If it will play one
and not the other, most likely a laser assembly gone bad. I dont work on
these much, but have haerd enough about em.

"Ken G." wrote in message
...
I also work on these .. my questions are what is the probable cause for
these to stop reading the blue backed disks ?

I just had one here that would read the silver PS2 games fine but
refused to read blue disks or DVD disks . A good cleaning did no good