Need some information on howto work on your Thinkpad?
I thought I would provide links I have come across describing the various upgrades and/or replacements you can perform on T4x series Thinkpads. These are all useful guides I hope you will find helpful.
The first place to look that covers all the information you will probably need is the IBM / Lenovo support website. Just enter your model number and go from there..
ThinkPad T40, T40p, T41, T41p, T42, T42p
A very handy guide also from the IBM/Lenovo site is the Hardware Maintenance Manual. This manual provides detailed instructions from replacing parts to error codes..
Thinkpad T40 Hardware Manual.
Now for the website links I’ve found useful..