Electrical 2001 S80 non-turbo 97000 miles automatic

[Armenia]

Please help Car was parked, everything was fine. Six hours later nothing worked! NOTHING except the radio when the key was turned to position two.....no dash lights, no starter, no NOTHING! I replaced the battery, it did not help. It is like a security system has shut the car completely down. What do I look for? All fuses are fine in the car and engine compartment. No one was near the car - it was in plain view. Any suggestions? Thanks for looking.

[MadeInJapan]

If it's the immobilizer, try locking and unlocking your car twice with your key fob and see if that works. If not, try that again, this time with your key. Make sure you don't have 2 sets of keys for your car on the same key ring.