What version is this PS2?....

[rubber2k1]

I need to know what version this PS2 is cause my neighbor wants me to install a no-solder chip. Here is the info:

model 30001R(usa)
Serial U154....
8 screws on bottom

[kooldraco]

I could be either a Ver. 4/5/6. Read this:
http://www.psxmodchipcentral.com/shopping/installGuide/version.html