T5系列机器reset

I tried the above on the T5220, with no success.

However, I was successful using the 'default' login.

Once you've set the jumper as described above, log in as 'default':

login: default
Press and release the physical presence button.
Press return when this is completed...
Password:

Press the remote access light when prompted above. Then log in with the password 'defaultpassword'.

You'll be logged in with admin access and will be able to reset the root password.