These CX20084 chips are from other Walkmans, so they are used, but they all work properly. Each one will be installed on WM-D6C or WM-D3 to test to ensure that they function properly. Before shipping, I will record a test video for your confirmation. The price is for 1 piece. When using the wrong or unstable power adapter on the WM-D6C, the CX20084 will be damaged. The bad phenomenon is usually running very fast, or running as soon as the power is turned on, or pressing the button but no response, etc.Therefore, it is recommended that you always use batteries. Replacing CX20084 requires certain soldering skills, so please evaluate it carefully before deciding whether to purchase it.