• Under normal conditions, after pressing the reset button, the safety relay should light up three green lights (as shown in the figure).

1. If the safety relay does not light up, you need to check the power supply to the safety relay and measure the voltage at the A+ and A- terminals on the relay with a multimeter (the normal voltage should be 24V).

           If the voltage is normal but the relay still does not light up, then you need to replace the safety

           relay. If the voltage is 0, then you need to troubleshoot the power supply to the safety relay. Since

           the safety relay and the mainboard are powered by the same supply, if the mainboard is

           functioning normally but the relay has no power, it is likely that the circuit is broken or there is a

           poor connection.

             2. If the relay only lights up one green light at all times, the following steps should be taken to

                 test the cover open protection feature:         

Measure the continuity between S11 and S12 at the relay interface, as well as between S21 and  S22. If the switch is continuous, measuring whether the reset button is continuous when pressed (measure between S33 and S34) is also necessary (as shown in the figure). If any of them are discontinuous, it indicates that the corresponding switch on the circuit is damaged and needs to be replaced.