I attempted to change a failed halogen GU10 lamp in a run of 3 but when I turned the light switch back on all 3 failed. I have since tried another lamp with no luck, I have checked the connections all seem tight with no signs of damage. The light switch is a 2-way switch and the other light in the dinning area works fine. I'm not sure what to check next before I call an electrician, any ideas? Thanks in advance