If a data logger is not registering any tips, what can be done?
The following are some suggestions to try:
Check that there is a solid connection to the reed switch. The screws should be tight, and the wires should have a solid connection to the screws.
Try switching the connection from the current reed switch being used to the secondary reed switch connection.
Check that the cable is connected to the correct input on the data logger. Take the two wires on the other end of the cable (the sensor side) and touch them together. The data logger should register a tip. If the tip registers, the issue is with the reed switch. Replace the reed switch.
If the data logger still doesn't register a tip, try using a different cable.