Generally speaking, under normal circumstances, the yellow and green light flashing when charging the kindle may not be charged for the following reasons, the first reason is that the charger used is insufficient power supply leading to normal charging, you can try to replace other chargers.
The second case is that the data cable used to charge is not well connected, resulting in poor contact of the charging interface, you can try to replace the data cable, the third case is that the built-in lithium battery of the Kindle is damaged and can not be charged normally, which can be solved by replacing a new battery.