Just dusted 2 old V240 and powered them on.
Well one of them …
Of course no mention of the ALOM passwords but I was able to find out one. Unfortunately the other had of course a different one which I couldn’t guess.
Lucky me, that box was able to start the OS so …
cd /usr/platform/`uname -i`/sbin #which is /usr/platform/SUNW,Sun-Fire-V240/sbin scadm userpassword admin #to change the password of the SC ALOM
And change the password to something to forget the next time again.
Note: scadm works on the V series but not on the T series servers.