Hi, thank you for this guide !
I successfully managed in disassembling my Elitebook 840 and change the fan.
-However-, when reassembling it, I was surprised to see that my touchpad doesn't work anymore (but the mouse nipple works perfectly). I don't really understand because I didn't disconnect anything except the keyboard (that is not connected on the same ribbon cables, so...).
I tried to reinitialize it from the Windows panel, but no luck.
Do you have an idea of what could be wrong ?