The line was failing at -136 dBc. We tapped everything on the tower and start tapping at the hardline connector in the shelter. As soon as we tap the lower hardline connector, PIM levels jump to -119 dBc. Tower crew takes apart the connector, gives it a little dry air and calls it good. Line fails tap test. A short inspection and the PIM Technician identifies the issue with the connector. The tower crew reworks connector and system passes. Tapping....the first step of troubleshooting.