Hello and welcome to the Forum

Seems all T40,T41,and T42 system boards are ATI-based, so you are out of options there. System service parts list for T40/41/41:
http://support.lenovo.com/en_US/detail. ... R-46474#15 (see part #15).
However, some R51 system boards are Intel-based. System service parts list for R50/51/:
http://support.lenovo.com/en_US/detail. ... R-46474#15 (see part #18).
So what some creative folks have done, (seeing the R51 and T40/41/42 are cousins), is to swap an R51 board into a T41 successfully

:
viewtopic.php?f=2&t=81540 and
viewtopic.php?f=2&t=65505 (You're a little late to the party LOL. These threads go back to 2008). Seems like it can be done with an R52 board also, but R52 uses DDR2 (PC2-4200 RAM) and CPU is different also.
If you want even more info. use this advanced search of the Forum:
http://www.google.com/advanced_search?q ... as_qdr=all and enter keywords such as "r51 t42 motherboard" which is all I did since I remembered running across threads discussing this issue before. Leave the other search modifiers blank at first.
I will try these Frankenpads one of these days myself- seeing I have a house full of T40/41/42/R51's all over the place. I haven't read through all of the threads but a quick scan seems to indicate it's pretty straightforward. Reading through those threads will be
your homework thanks to those precious little kids of yours
BTW, if you're interested, I think I have an R51 or R52 Intel-based board I can part with. I also have a
brand new (old stock) T41 type 2374 board I can get you. Yes, it's also ATI-based, but it's brand new so hey... Really, it's a lot of work and test of patience swapping out boards, especially if you are a newbie as you don't mind admitting, and the price of T40/41/42 machines have gone down substantially. It might just make more sense to remove the memory and hard drive from that machine and sell it
as is on Feebay or a Craigslist Canada type site (honestly stating the water damage). Then just pick up another complete T40/41/42/R51 machine which has been tested against GPU failure. They are pretty inexpensive nowadays. You would be able to re-use your RAM and that very nice Samsung 160 hard drive (may just have to update a few drivers). That's probably the easier path. I have some machines available to choose from. I could offer one to you bare-bones without memory or hard drive. Check my listing here:
viewtopic.php?f=11&t=98420 (and I have many others besides those). Feel free to email me if interested (see signature below). I have many satisfied Canadian customers and some relatives in Toronto
Have a great day,
Daniel.