Normally, when all the lights stop working usually one of most common reason is a tripped electrical breaker in the service panel or the GFCI of the electrical outlet.
This issue is very common in seasons of very heavy raining, lightning and storms.
You need to know where is the problem!
Is on the electrical side or on the lights system?
The first step to do is checking if you have electricity output in the electrical outlet (where you have connected the transformer), and doing that you can verify if the problem is about the electricity in your outlet or the lighting system like the transformer or a broken main wire.
How to do that? The easy way to check if you have electricity in the electrical outlet just connect your phone charger and plug your phone to see if it start charging.
If it doesn't work it means that you don't have electricity in that outlet (where you have connected the transformer). Now you know that you don't have electricity in the outlet and also you know that the problem is not on the lights side and all you need to do is this simple steps:
1. If the electrical outlet is a GFCI version just reset it.
2. Check if you have a breaker that is tripped.
These are the two most common solutions when all lights are out specially in storms and heavy raining season.
What to do if now you have electricity in the outlet but lights still not working?
Simple, just check if the GFCI switch that is inside of the transformer is tripped.
The switch HAS TO BE TO THE RIGHT SIDE.
If it is left side it means it is tripped and lights are off.
Sometimes when there are storm or heavy rains, the transformer trip its interrupter to prevent burning all the bulb lights or even the transformer.