Make sure your desired surface, whether it be a headboard, table, desk, or other edged surface, is anywhere between 1” and 3” thick. Any surface that is less than 1” thick won’t securely hold your lamp, while anything over 3” is too large for the clamp to attach to. Gently clean your desired surface and make sure it is hard, flat, and sturdy. Try picking another surface for your lamp if necessary. You should also ensure that the clamp isn’t filled with dirt, dust, or other debris. Gently wipe it with a soft, damp cloth to clean it. Do not use the clamp if it is damaged or visibly malfunctioning in any way. Check that the clamp is firmly attached to the lamp.