The 550 uses Apple part #661-2568. The 1GH uses 661-2748
Apple Part Number: 661-2539, 661-2539-A, 661-2568
LTN152W1-L01, LP152W1 (A1AP), LP152w02 (A1)
Compatibility
PowerBook G4 Titanium Mercury (400/500), PowerBook G4 Titanium Onyx (550 & 667) VGA Model
Apple Part Number: 661-2748, 661-2748-A-R
B152EW01
15.2-inch (1280X854) LCD panel and upper case assembly for a 667MHz / 800MHz / 867MHz / 1GHz (DVI) PowerBook Titanium.
This LCD assembly will not function properly in the 400 / 500MHz (Original) or the 550 / 667MHz (Gigabit) Titanium Powerbooks.