Have had my opensprinkler system for a few years now, and noticed the sprinklers were not turning on. After investigation, i found if i unplug or plug the power, the screen flashes yellow for 0.5 second, then nothing. At one power cycle, i got a chattering sound liek a relay, but nothing else, all other times have been the brief flash, then nothing. Is there anything else i can test on the board. Visually everything looks OK.
I did notice that the transformer is outputting 30VAC – would this be considered overvoltage and cause the unit to shut down? I don’t have another transformer here to test
Do you know what’s the hardware version? Is it OS 2.x? If it has a USB port, the first thing you can do is to remove the 24VAC power, but instead plug in a USB cable connected to a USB power source to see if the controller powers up and displays anything. If so, it’s likely 24VAC->5V conversion has a problem, and there is a work-around (basically using USB to power the controller) to continue using it.