The PS3 does not have a traditional "Safe Mode" like PS4/PS5 or Windows. It has a Service Mode (for firmware recovery) and a System Recovery Menu accessed via button combo.
PS3/UPDATE/PS3UPDAT.PUP.Warning: Option 5 wipes everything. Always try 3 → 4 → 5 in order. Backup saves to USB (Settings > System Settings > Backup Utility) before any restore.