When you push the slide down on the side, there's a wire that it pushes down inside the toaster. If the wire gets bent down a bit, pushing the slide down doesn't push the wire down enough. The wire is like a teeter totter. When it gets pushed down, it closes the circuit which turns the toaster on. The reason why the slide doesn't stay down is without energy, the electromagnet doesn't get engaged. That's what keeps the slide down. You need to remove the 4 screws on the bottom, and the 2 screws that hold the legs on that also hold the side on with the slide. Once the side is off, take a pair of needle nose pliers and bend the wire up a bit that acts as the teeter totter.