Hi Bumbly, considering that the hinges are the ONLY moving part, this IS the source of your problem. You will have to get the pins out, take a flat blade screwdriver and a hammer placing the blade angled on the head of the pin and tap up with the hammer, they will eventually loosen and come out. Once you have them out take some sandpaper to them removing any rust/buildup, coat them (and the inside of the brackets) with 3in1 oil, NOT WD40 (it evaporates relatively quickly). Problem should be solved. Good luck!