Taptic/Vibration engine not working

Ok so long story short, the iphone got wet. They had changed the battery not long before but it seems they didn’t apply the glue well so it was cleaned inside and out. The first thing to go was the vibration motor, so i turned off, opened it and started the fix . i changed the taptic motor, lcd, and flex charge port. All works perfectly well in the phone except the vibration. i have already done everything (dfu, reset etc.) and still nothing. i haven’t still reseated the lcd until atleast i know what could it be. any ideas will be greatly appreciated.