Please explain the true facts.friend The machine was being used normally with the assistance of the after-sales team. We are not sure whether you used unstable voltage or a generator. The vending machine is not allowed to be used with a generator, as this will cause unstable voltage. The manual sent also states that the generator should not be used. After the black screen occurred, the requirements of the after-sales team were to use a multimeter to check if it was a voltage issue. However, the customer was reluctant to cooperate. Please refer to the screenshots for details. All we have stated are the true facts. It is also feasible for the customer to borrow a multimeter from a friend. We have never forced them. We have also explained that if it is a quality issue with the machine, we will send replacement parts and reimburse the cost of the multimeter. If it is caused by the customer using the generator, this is completely not our responsibility.