Three days ago my 75/15 MPPT controller stopped working. I have 200W of solar panels installed in April. It had worked perfectly. When I discovered it wasn't working I disconnected the battery positive, reconnected and they worked again. 36 hours later they stopped working. On both occasions the app showed them as off, the blue led is flashing.
I have since, on advice covered the panels, disconnected and reconnected the battery positive and then uncovered the panels. Still not working.
The other odd symptom, the voltage on the PV wires at the controller is as expected 21v. If they're connected to the MPPT controller the terminal block gives a voltage of 2.1v. If the battery is connected then I get the battery voltage.
Thanks in advance