I have a ps2 (SCPH-39009) doesn't play 'CDs' at all. How can i fix this?

I dont understand why you would want to fiddle with the 'voltage' to play CD's but what will help you is this...
On the CD-ROM drive itself there will be a screw a little bit further back where the lazer block is toward the back ont he drive. This will adjust the height of the lazer and will fix 90% of all read problems.
Opening your console at all with validate your warrenty so please dont do it unless you really REALLY want to and if your stuck to find the screw that you need to adjust there are pictures online im sure that will show you.

Andrew Joseph
August 2007