Resetting SP password using jumper P20 doesn't work on Sun Fire x4600 M2
Solution 1:
Unfortunately, I have no extra insight on the reason why the jumper wouldn't work, but you can reset the password using ipmitool, with the commands:
ipmitool user list 1
<Find the appropriate user id in the returned list>
ipmitool user set password <userid> <newpassword>
Adapted from How to reset iLOM root password on Sun/Oracle X server.