Hi @chalke,
Were the original batteries OK inasmuch that they hadn't leaked?
If they had check that the battery connection terminals in the camera are clean and bright and not affected by any corrosion.
You could try cleaning them anyway using a Q-Tip lightly moistened (not dripping) with vinegar or better still if you have some 99%+ Isopropyl Alcohol.
It could be after all this time that there's a layer of verdigris on the contact surfaces preventing a good electrical connection.
Also double check that you inserted all the batteries the correct way ;-)