T40 series cross compatibility and other questions

[ncovert]

I've recently dug up my old T40. And I remembered why I had retired it - flaky motherboard. Sometimes it'll work - but it crashes within seconds of starting up. Most of the time it just lights up and runs the fan at full speed. I'd rather not waste time reflowing the board - the thing has been to hell and back (missing several plastic pieces, a few keycaps, most of the screws, etc.) and I'd like to get me one that doesn't fall apart when you open the lid.
It still has its hard drive, but I can't get the files off it by plugging it into an IDE to USB adapter - my main PC won't let me change the permissions.

So my question is, if I were to get a better model like a T42 and pop my T40's hard drive into there, would it boot up just like old times? In my prior experiences with other systems, Windows XP tends to bluescreen within seconds of loading on different hardware. But I figure the T40, T41, and T42 are similar under the hood so that's why I ask.

My second question is - what exactly are the differences between each model? From my understanding, the T43 takes DDR2 rather than first-gen DDR RAM, the T42 has Radeon 9000 over 7500 graphics, and the T41 brought gigabit ethernet to the table. Are there any other differences?

[RealBlackStuff]

Basically you could use any motherboard from a T40/T41/T42 and R50/R51 and move all parts over from your old T40.
The only difference you will find is between the fans for Intel or ATI graphics.
ATI fans will fit on all boards (Intel or ATI), while Intel fans only fit Intel graphics.
It is recommended to use 72W/16V chargers for all.

T43/R52 use different CPUs and DDR2 RAM, as well as different PCMCIA cages.
The rest is the same.

Finally, Intel graphics only supports XGA on 14.1" machines and XGA plus SXGA+ on 15" machines.
ATI can support XGA, SXGA+ and UXGA (and even QXGA).
Each resolution needs a different LCD-cable and inverter.
To be sure, check the HMM (manuals).