The answer to 'my junction box won't turn on' is that there could be several common causes, such as a tripped circuit breaker, a faulty switch or outlet, or a problem with the wiring. The symptoms may include the lights or appliances not working, and the junction box not providing any power.
To troubleshoot, first check the circuit breaker and reset it if it has tripped. If that doesn't work, you may need to inspect the wiring and connections in the junction box. This is a job best left to a professional electrician, as working with electrical systems can be dangerous if you don't have the proper training and experience.