No, the original TiBook I had was 400mhz. I'm the third owner (the second was my mom and the first my sister's old boyfriend). I got it in 2002. It's on it's second logicboard and that's failing which is why I replaced it with the 1Ghz TiBook.
I have had the opposite experience of almost every TiBook owner. My hinges on the Ti400 did NOT break. But the case broke AROUND the hinges! So when I swapped the displays I had good hinges.
The old LCD is of a lesser resolution so my son is not getting the full resolution. I did buy an LCD pull from a 1Ghz machine, but in my rush did not notice that it came without hinges. I'm either going to try my hand at finding and replacing hinges or find another LCD pull that has hinges for a good price.
Replacing the LCD was no issue. I've replaced the logicboard on the first TiBook and this was marginally more complicated (because to get the LCD off you have to remove the logicboard). I've replaced the LCD on a 12" AlBook, a 17" Albook and lots of other parts on the 17" Albooks. The only PB I don't have and have yet to work on is a 15" Albook. So, again, swapping the screen was no issue.
For some reason, eBay sellers seem to think that a bad LCD compromises the entire Mac and they sell it for parts or whatever. Just replace the LCD. It's no big deal. I've now gotten three good Macs for firesale prices because sellers don't seem to be able to understand this. Oh well, my gain.