Tascam Cd-401 Mkii Service Manual Link

You can find or purchase the service manual through these specialized providers:

You cannot calibrate a Tascam CD-401 MkII without putting it into "Test Mode." The service manual provides the key combination (usually holding specific buttons while powering on) to disable the tray lock, spin the motor without a disc, and access the potentiometers for laser alignment. Tascam Cd-401 Mkii Service Manual