There are a total of 7 Decayed Chests in God of War Ascension. Finding all of them will earn you the "If it ain't broke..." gold trophy. To reconstruct the decayed chests you need the Amulet of Uroborus which is acquired automatically in the beginning of chapter 13. Stand in front of the chests and press L2+Square to reconstruct them. There is no need to loot the chests. If you die or restart checkpoints you will have to do it again! Doing this via chapter select won't unlock the trophy.

The first chests is in chapter 13 and the last one in chapter 19. So you need to play through all these chapters again if you missed something.

TIMELINE:
#1 - Chapter 13 - 0:05
#2 - Chapter 14 - 0:45
#3 - Chapter 14 - 1:08
#4 - Chapter 14 - 1:25
#5 - Chapter 14 - 1:41
#6 - Chapter 16 - 2:04
#7 - Chapter 19 - 2:20