Either you moved a cable or damaged a fan. If possible you should always jam up any fans with a pencil or other object to keep them from spinning when blowing them out.
Of course your all-in-one opens, how do you think they repair it or even put it together. If it is an apple then you need special tools, if not apple then there should be screws on the back of it. You sold be able to google online and find a disassembly manual.