2011 Toyota RAV4 dashboard lights off when headlights on

What is your question?

I bought new 2011 RAV4 6 months back and current milege is 5000 miles. When I switch on headlights, then dashboard lights are going off and I can't see anything in the dashboard. If I turn off headlights, I can see dashbard but not the road. What could be the issue ? Do I need to go to Toyota Repair center ? or any lights gone ?