This guide is for hinge type K19. This hinge type is used by the following models:
Some colors in the pictures may differ for your model. That is fine, what matters most is the shape of the hinge piece.
The U-shaped plastic base piece must be oriented as shown for it to fit beneath the metal keyboard hooks. The main hinge mechanism will lock into this U-shaped frame piece later. If the U-shaped piece is still intact on your keyboard, there should be no need to remove it, and you can skip to step 4.
Place the bottom edge of the base piece under the two metal tabs on the base of the keyboard. This works best at about a 45 degree angle.
Secure the sides of the base piece into place, one side at a time. In this example, the left side is being secured first. You can bend each side of the plastic piece a bit to duck it under the metal tab. All three sides of the U-shaped frame piece should now be hooked under the metal tabs protruding from the base of the keyboard.
If your keyboard is missing the rubber spring piece, place it in the center, with the large end down. It will be held in place by the surrounding hinge bracket in a moment.
Insert the bottom two black plastic tabs on the hinge mechanism into the plastic base piece, one side at a time. In the image below, the left side is being tucked into place first.
Push down and towards the top of the hinge to tuck the remaining top two white plastic tabs into place. A bit of even pressure should be enough to click the two tabs into place on the plastic base piece.
The hinge assembly is complete and should now look like what is pictured. You can now check that the hinge works properly by pressing down on it. If it springs back easily, it is ready for the key to be attached. If it doesn’t feel right, you may need to remove the hinge one tab at a time and try repositioning the rubber spring piece.
Align the key on top of its place on the keyboard, and press down evenly. All four corners of the key should click into place.