The control panel is flashing Zone 10, it has an error. Zone 10 is the front flowerbed. Not good.
I do not know the location of the Zone 10 control valve. It was buried over 15 years ago, long forgotten. The install of the sprinkler system precedes digital pictures, and was installed by someone else.
It is going to take a lot of prodding and digging to find the valve. Fun times.