One of the LPARs is in ‘Open Firmware’ state.
I opened the vterm and the option list was displayed:
“Open in progress
1. Select Language
2. Setup Remote IPL (Initial Program Load)
3. Change SCSI Settings
4. Select Console
5. Select Boot Options
X = eXit System Management Services
Type menu item number and press Enter or select Navigation key:
Service Management System (SMS) was closed and the machine was restarted.
Once brought it back again, it worked.
Power Outage interrupted a normal boot-up of the machine.