I always persevere to resolve a problem, even when they are challenging.
I went to repair a dishwasher that was showing an E6 fault. This typically means that water has leaked into the base and activated the flood switch, and causes the machine to stop working and beep. Normally I would remove the water from the base and repair the leak. However in this unusual situation, there was no water in the base.
I tested the machine and heard an unusual buzzing noise from the door switch. After replacing the faulty door switch (which had shorted and triggered the flood switch), the machine was repaired.
One happy customer.