The electronics room was a bit untidy so I ripped out the shelves I made from old pallets and made some new ones from scaffolding boards. These shelves are very strong, I was sitting and standing on them and they didn't bend more than a couple of millimetres.
More tidying needed, but they make much better use of the space, especially with the IKEA boxes. They don't smell bad like the old pallets did, either. Turns out it was the legs of the shelves I made that were smelly. They came form the old garage roof and were some odd type of pine that probably didn't play well with the moisture in the garage.