The version 1, 2 and 3 PlayStation2 all have 10 screws on the bottom of the unit.

SCPH30001 v1 = Serial# begins U1
SCPH30001 v2 = Serial# begins U0
SCPH30001 v3 = Serial# begins U1 Date 1A
SCPH30001 v3 = Serial# begins U2 Date 0D

The version 4, 5, 6 and 7 PlayStation 2 all have 8 screws on the bottom of the unit. The 4 and 5 also have the electrical warning stamped on the bottom of the PlayStation 2 case.

SCPH 30001 v4 = Serial# begins with U0
SCPH 30001 v4 = Serial# begins with U1
SCPH 30001 v4 = Serial# begins with U2
SCPH 30001 v4 = Serial# begins with U3
SCPH 30001 v4 = Serial# begins with U4
SCPH 30001 v4 = Serial# begins with U5
SCPH 35001 v4 = GT3 Edition

There are 3 different motherboards for the SCPH 30001R – Version 4, 5 and 6

SCPH 30001R v5 or v6 Motherboard
SCPH 39001 v7
SCPH 50001 v9
SCPH 50010 v10
SCPH 50004 v11

The version 12 PlayStation 2 is the new slimline PSTwo model with the following model numbers:

SCPH 70011 CB v12
SCPH 70012 CB v12
SCPH 70002 CB v12
SCPH 70003 CB v12
SCPH 70004 CB v12
SCPH 70000 CB v12