I messed up my ps2 hd7 lens...

They were made by different manufacturers and so some adjustments need to be different. On the PS2 some things are controlled in software, hence different values within the EEPROM.
There were at least two different SONY lenses too. Different values were used for both.

According to @l_oliveira, if you install the wrong optical block type (i.e. a KHS-400C in a console configured for the SF-HD7), it would try to read discs normally first. But if it fails to, then it will eventually try using the defaults for the other optical block model. Until then, it'll be used to focus and so on, so it probably isn't very healthy.

 

I know this is an older post but this has just really helped me. I was wondering why a KHS-400C wouldn't work properly in my V10 which originally had an SF-HD7 laser. It would sometimes read the discs fine but would literally take about a minute to read a PS1 game and keep spinning then stopping and clicking. Another word of advice to people is that a KHS-400C using the SF-HD7 eeprom setting is a REALLY bad idea. It makes the lens jump too high and hit the disc twice while trying to focus and can scratch your games.

Anyway I reprogrammed the eeprom and now it is absolutely perfect and even reads a PS1 game in like 4 seconds

I also have a V6 that would sometimes read a game right away and other times start clicking etc. for about 10 seconds then read, even with a new laser. I used that eeprom programmer on it and now that is 100% perfect too

I guess the V6 must have originally had a KHS-400B.

I really wish I'd known this. I haven't really done much with PS2 consoles until the last few months but I spent ages trying every angle / skew angle and was just short of banging my head against the wall. All I could do was confirm that it was definitely motherboard related as to why it would struggle to recognise a game or wouldn't read CD's etc. I then thought that something was wrong with the boards until I realised the faulty SF-HD7 could read a CD no problem yesterday and the new KHS-400C one couldn't.

I'm just glad I found this info and fixed both of them now though and they both have new KHS-400C's