TouchID not working properly
Customer came in and wanted me to change her screen. I didnt have time at the moment so i had my trainee do it. He has done iphone 6 repairs many times so i trusted him with this. He was a litle bit sick that day but wanted to work anyway.
Everything worked fine except for ToucID. So i took a look and found some liquid on the connector between the button and the LCD backplate shield. The liquid probably came from my sick trainees nose. I removed the liquid and cleaned the connectors with alcohol. I put the phone back together and turned it on.
the tocuh ID error message was gone and the button reacted to my finger.
Then the customer came and the TouchID didnt work any more. But in the security settings, the button for setting up Touchid is not greyed out. Its usually greyed out if touchID is not working as normal. If you try to set touch ID up it gives an error message saying "failed" Can not configure touchid.
I've change the the LCD backplate many times and double and triple check all connectors.
I've added some pictures. I hope anyone have a solution.