Very simple on Lenovo T430 model. Carefully lift the plastic cover over the on-switch with small, flat screwdriver. Cover goes across top of KEYBOARD. Be careful not to crack cover. Switch is just a solid plastic button that is probably worn down. Actual switch is silver pressure button under plastic top button. Just push that button with blunt object and laptop should start. Keep plastic bar cover loose or snap back on without plastic button. I just suspend power on logoff so as not to wear the real on button out and only use if I need to or forget to suspend. Actually good as additional security method.