Use a non contact voltage meter to check and see if you have power to the switch. The following method will address both problems at once.

Multiway Switching Wikipedia
Troubleshooting 3 way switch wiring. Ceiling fan 3 way switch wiring. This is the same arrangement as the second diagram on this page with a fan in place of the light fixture. 3 way switch troubleshooting diagrams. Now go the other switch location. In this case the traveler wire and load wire were swapped and repairing the circuit involved switching them back. Each 4 way switch in between would worsen the odds by a factor of 3.
The steps i am going to describe may not be the most time efficient way to troubleshoot a 3 way circuit. At the first 3 way switch the black wire that leads up to the light fixture is connected to the black wire of the 3 wire cable. Disconnect switch and connect all 3 wires together with a wire nut. Using a continuity tester check continuity between the common black terminal and each of the traveler terminals brass colored of each 3 way switch. Common problems with 3way switches and how to fix them. In this wiring the source is at sw1 and 3 wire cable runs between each switch and the ceiling fan.
Here a ceiling fan with a light kit is controlled with two 3 way switches. Since a 2 switch system has 3 wires to be connected to 3 terminals at each box it works out that only 1 out of 9 possibilities will work. Touch the probes to the 3 wires removed from the switch until you get a reading on the tester indicating continuity. Switch b disconnect all the wires and connect two wires together. Troubleshooting three way switches will involve determining whether the switch is bad or not. How three way switches work.
Turn the power on. Remove the two 3 way switches so you can access the switch terminalsthe wire connections do not have to be removed. A three way switch will always have power at two poles. At the switch where you found power in step 2 put the other 2 wires you removed from the switch together and wire nut them. Sometimes one of the switches has become defective. Grounding the 3way switches the ground wires are all bonded together and one of the ground wires is attached to the ground screw found on each 3 way switch frame.
There are many ways that a three way switch can be wired but usually power or the light fixture connect to the load side of the switch and traveler wires run between traveler screws on both switches. One would be for the power. To id the wires o a 3 way switch all you need are some wire nuts. Sometimes a 3 way circuit doesnt work because someone tried to replace a defective switch and did not properly connect the wires. Set the electrical tester to the continuity or ohms setting. Test a 3 way switchturn off power to the switches at the circuit breaker and using a tester make sure power is off.
You can use a voltage tester to find out. How complicated can 3 way switch troubleshooting be. Turn power off label the switches a b.