PlayStation 2 versions
Take a look on the back of your PS2 console, you will see a label similar to the one below. The numbers that follow SCPH are your PS2's model number. This can help you identify which version you have.

PS2 console versions 1, 2 & 3 Identification
V1 - First PS2 released in Japan
V2 - First PS2 released in USA
V3 - First PS2 released in UK & Europe
Turn your console upside down and have a look at the bottom you will see several square screw caps, if you have 10 of these caps you have a PS2 console version 1, 2 or 3 if not, then you have 8 screw caps and your version will be 4 or above.


PS2 console version 4 Identification
The model number can be
SCPH- 30000 , 30001 , 35001 , 30002 , 35002 , 30003 , 35003 , 30004 , 35004
You console will have 8 case screws.
PS2 console version 5/6 Identification
The model number can be
SCPH- 30000R, 30001 R, 30002 R, 30003 R, 30004 R, 30006 R
But also some 30000, 30001, 30002, 30003, 30004 PS2 consoles have a V5/V6 main board.
PS2 console version 7/8 Identification
If your model number is SCPH- 39000 , 39001 , 39002 , 39003 , 39004 , 37000
PS2 console version 9/10 Identification
If your model number is SCPH- 50001, 50002, 50003, 50004, 5000X
These consoles will either be Black or Satin Silver in colour and have an Infrared remote sensor between the Power and Eject buttons. The only difference between them is the mainboard the version 9 has the GH-023 and the V10 has GH-026.
PS2 console version 11 Identification
This console version does not exist .
PS2 console version 12,13,14 Identification
These consoles are all PS2 slimline models, there is a few variations but no significant changes.