Solved! I have a Sony CCD-TRV57 that often displays a C:31:11 diagnostic and the cassette tape/transport door will not open (eject). W

[markamoor]

Concerns Sony 8mm CDD-TRV57 Handycam

 

[hang-the-9]

You will need to have a repair tech look at the device, there is no magic fix for a physical issue like the cassette door not opening.