Do you mean OpenSprinkler 2.0? There is no version 2.8 yet 🙂
Yes, the station 1 triac seem to have burned, and it can certainly be replaced. If you want to do self-diagnosis, here are my suggestions:
1. use a multimeter to test the resistance between VIN-GND, and also between VCC-GND. Check the resistance values, they should be at least a few kilo-ohms. If they are below a kilo-ohm, something is shorted and probably more chips have to be replaced.
2. use a diagonal cutter to cut the top three pins of the damaged chip (it’s a triac). this chip is likely to have shorted, and cutting the leads will isolate it from the rest of the circuit.
3. try to use a USB cable to power the controller, see if the LCD lights up and displays messages.
4. if the above passes, power the controller with 24V AC and check if everything is working fine.
The triac can be replaced with a soldering iron — even though it’s a surface mount component, it’s fairly large, and can be easily desoldered and re-soldered. If you need replacement parts, please send an email to [email protected].