[Melodica-Me]

Bruce, what you need to do first is now take the back off completely. Then check for any tears in the gasket. If none are found, place the back on a flat surface to check if flat and even. If the back is flat and even, test the back on the Melodica and see if it sits flat. If it does not check for abnormalities. If it fits flat. Place the back on the Melodica and put all the screws in 1/2 way in so the back is still loose. Not turn each screw 1 full turn each before moving to the next. Repeat this until the back is on securely. Do not over tighten, but do not leave loose. If you install a screw crooked it will feel like it is tight but in fact it will be loose. If you feel you have done this remove only that screw and reseat that screw. Once you have all the screws in you can check for leaks. If you have a flex hose
this will help. With the flex hose installed turn the Melodica on it side and pour a little soap and water mixtures along the joint to see if you can see the leak when blown into it. If you do tighten it up a little more at the nearest screw, once again do not over tightens. If you still have leaks, mark these areas with a white grease pencil or with some masking tape. If leaks persist, open the Melodica and check at the areas where you placed the marks and check gasket there. If you see a tear or crease in the areas marked you can melt a little bees wax and fill the crease or tear to a flat even surface and replace the back and start the closing process over. Sometimes it’s just easier to replace the gasket but in a pinch this is a easy way to fix it.
I hope this helps you a little.
Melodica-Me
Monsters of Melodica