The device passcode is only required for testing the device before and after the repair. This simply involves testing the device, and at no time will your personal data be accessed. However its helpful if you provide this to us.
If you have not allowed our technicians to fully test the device. Either the phone was password protected or not accessible so we could not fully complete diagnostics / fault finding. We will not cover additional faults as was unable to test due to security. It is the customers responsibility to provide a passcode or wipe the device of personal data before shipping so we can test thoroughly.