Broken control key after heat sink replacement

No, like I said, the key does nothing when pressed.

In that case its time for a new keyboard as your key switch is bad ;-{

The cables connection is not the issue as then you would have multiple keys messing up. Think of it this way... A matrix of lines (X & Y) each switch connects one X wire with a Y wire to then tell the computer the input of that key. If one line was damaged then and key which connects to this line would also not work. Clearly thats not the case here so the given switch is bad.