Donna,

The repairing makes sense.

Hilkiah found the book of the law, in there.

Was it under, or behind, some rubble?

Things must have been really messed up during the 55 year reign of Manasseh, and the 2 year reign of his son.

Manasseh even did the following:

I Kings 21:7 And he set a graven image of the grove that he had made in the house, of which the LORD said to David, and to Solomon his son, In this house, and in Jerusalem, which I have chosen out of all tribes of Israel, will I put my name for ever:

II Chronicles 33:7 And he set a carved image, the idol which he had made, in the house of God, of which God had said to David and to Solomon his son, In this house, and in Jerusalem, which I have chosen before all the tribes of Israel, will I put my name for ever:

Was that image placed in the holy place, where the table of shewbread was?

Or was it even placed in the most holy place, where the ark belonged?

If that is the case, then perhaps the priests may have moved the ark out, before the desecration, similar to what they did a few years later, when Nebuchadnezzar came?