I checked my breakers and they look okay, so why won't my switch work?

Breakers must trip even if the handle is held in the on position by force.

A common design disconnects the handle from the internal mechanism when the breaker trips, allowing the contacts to open even if something is holding the handle.

To turn the circuit back on, the handle must be moved to the off position to re-engage the internal mechanism, then to on to close the contacts in the breaker.

Designs with indicators have been available from some vendors.

If you turn a breaker back on from a tripped position without engaging the internals it is usually very easy, unlike the force necessary to compress the trip spring when the mechanism is hooked to the handle.