Hot on the heels of a touchpad swap in my “new” Thinkpad T440P, come the next two upgrades: backlit keyboard and an IPS display. I shall call this machine Frankenpad as it’s rapidly deviating from the original configuration (20AWS series).
This is an old repair I did a while ago and posted on thinkpads forums. Reposting here to put it all under one roof. We have quite a few IBM Thinkpads X31 in the family. They are built like a tank and work well enough to keep using them despite 2003-2004 datecodes. One day two of them started exhibiting identical symptoms- they would just refuse to turn on. No lights, fans or other signs of life. Luckily I stumbled on a schematic on the web, so that was a good starting point.