“Fan Error” does not go away despite replacing the Fan

[blazicon201]

I tried repasting my T420 and ended up breaking the Yellow Tachometer wire. The laptop would refuse to go past the “Fan Error” screen despite whatever inputs I gave.

I replaced the fan thrice with exact same model numbers all sourced differently, and still the exact same issue.

[PhoenixR]

Sounds like connector port problem, probably you've broken not just the wire, worth checking the connector port and see if the fan starts at all(most likely not)