Different PS2 Laser Types

[eastsider_1]

I have noticed that there are several lasers used in the old ps2 models [obviously]. The first is the KHS-400A witch is used on the version 1 consoles. Also on the version 1-4 consoles is the KHS-400B laser. Next up is the KHS400C and SF-HD7/ KHS-400R. Now this is where im having trouble, i know for a fac that the version 5-7 use KHS-400C and HD7 respectevely, but the verstion 5 uses both whereas the version 7 uses only the HD7. I was wondering if there is a difference between the KHS-400R, SF-HD7. One thing i know is that the SF-HD7 is made by Sanyo, but on what models is it compatible?? Many sites say the "new" HD7 is compatible on Verison 5 thru Version 10 consoles, but this doesn't read as a "C" type laser on the version 9 console im testing it on. This is rediculous!!! I have knowledge of what consoles have what laser depending upon the model number and date code, but the DIFFERENCE and COMPATIBILITY is what i neeed. ANYONE interested/ knowledgeble in this area- please help.