I have an aqua trol hayward system. I just started it. On the board it says 2,80 and no green lights at all are on. What does it mean

This is a common issue. there is a componant on the circuit board called a voltage limiter. when there are power surges (by hydro company or by using a timer), this capacitor takes the surge to protect the circuit board. in your case, the limiter has blown.
you can either replace the circuit board or find someone to remove the limiter and solder in a new one. (its the round black disc to the right of the front display toward the top) in most cases, you will see a hairline crack in the casing or it may have exploded completely. i usually tap it with a screw driver to show customers the damage. FYI: i usually replace about 50 a year and never had one fail