Cause: Link from button to release lever has come loose
Solution 1: Add an emergency release hole
* Drill a small hole as shown appr. 94mm from the front:
* Seen from the inside, it should look like this:
* Now push carefully with a nail, your drill, or another sturdy pin to release the Thinkpad
Solution 2: Open Port Replicator
* If no Thinkpad is attached, you can open the Port Replicator like this:
* Remove 5 screws from button, pry with flat-bladed screwdriver at the marked points no the back: