If you are working on iBook and Powerbook screens, there's one thing that drive ya nuts, and that it is matching an OEM LCD to a specific 'Book. There have been a ton if 12" 'Books, and the LCDs may NOT be interchangeable.  Here is what I have personallly encountered.

iBook Clamshell

• iBook 500 MHz 12" - Samsung LTN121X1-L02

• iBook G3 12" (800 MHz)  LG. Phillips LP121x1 (A2C2)   or  Samsung LTN121X1-L02
• iBook G3 14" (700 MHz)  LG. Phillips LP141x11 (A2C1)

• iBook G4 LG.Phillips LP121x04 (C2)(K2)  or just (C2)

• PowerBook 3400c (yes really) Samsung LT121S4-105

PowerBook G4 15" 1.5GH   Samsung LTN152W6-L01