Repeat a complete functional test after delivery

Once the item arrives, repeat the test calmly in your own environment.

Use a complete sequence:

1. external inspection;
2. power-up or basic operation;
3. core functions;
4. the inputs and outputs you will use;
5. important secondary controls;
6. a reasonable extended test.

A previous video only demonstrates what was visible at that moment; it does not replace checking the actual item that arrived.

If you discover a problem, note when it appears, under which configuration and how it can be reproduced. This makes it much easier to explain to the seller or a technician.