There is no more awful feeling of filling your washing machine with a load of clothes adding detergent and hearing silence when setting to the on position. What is wrong? Why is it not working? These are the first questions that come to mind in this situation.
Either call a certified service technician or attempt to find the issue on your own. If you are moving forward on your own you should turn off and unplug the machine to avoid possible electrical shock.
One of the first things to check is if the machine is plugged in. Someone may have unplugged for whatever reason or the cord may have come loose in the back if the machine was bumped into or jarred since the last operation. If plugged in an ohm meter will be needed. Check the outlet for voltage with an ohm meter and the cord itself for damage. If no issues are found then you can ascertain there is some sort of mechanical issue.
The control panel will need to be opened to check the lid switch. Once control panel is opened find the harness plug and disconnect. The harness plug is what feeds the lid switch. Use the ohm meter to probe terminals on the non-green wires leading to lid switch. When the lid is closed the reading should be zero, and when open infinity. If this is not the case the lid switch needs to be replaced. You should search for your specific washing machine model to find the replacement lid switch.
If the lid switch is found to be functioning properly the timer should next be tested. Once all leads are off, set the ohm meter to RX100. Once again probe the leads a reading of 1,100 to 3,000 ohms means the timer does not need to be replaced.