Wifi- no hardware detected

Hello,

I bought a second hand macbook and I'm getting the error message "no hardware detected" for the wifi.

So far I have tried:

- Resetting the SMC and the PRAM

- Doing a clean install of Sierra

- Swapping in a different screen from another 13inch macbook pro which had a fully functional airport card and antenna

- Checking the pins on logicboard connector (there were no bent pins)

- Giving the logicboard a general clean up with some isoproply (just in case)

The bluetooth and camera work fine so I don't think it's something to do with the cable.

After trying the above, now the wifi icon doesn't appear on the menu screen or in network preferences.

At the moment I'm using a wifi dongle but I'd much rather get airport working again!

I'm at a loss for other fixes.

Any ideas? Thanks!