Cannot find all nails & pieces of wood

In the cave with the abyss. I have found most of the nails and pieces of wood but am now completely stuck. The hint button just makes a noise and does not show me anything.
Any suggestions?
Thanks,

I am also stuck with the wood/nails - the last plank will be revealed when you find all the nails, according to tips/tricks. The Hint button keeps going to the open box on sand, where I can't find anything in it. Has anyone found all the nails?
Thanks