Tip: Why no coffee came out?

Used an empty capsule, If there is no coffee flow out, pls told your customer try this tip: 1.dont press too tight when   fill in the coffee grounds 2.dont used extra fine coffee ground and 3.dont fill full coffee grounds into capsule rather than about 3/4 of coffee grounds is ok if the water cannot flow out normally, pls used the brush clean the lid very well