You can quickly test electrical devices to determine if they are working or not.
The reading with the device's switch off will show a reading of no conductivity (infinite resistance).
The reading with the device on will show some, but not infinite, resistance. If it shows infinite, the switch or other internal component is bad (heating element, etc.) and disassembly is required to fix the problem.
Want to save some time?
Here's a quick test you can perform on any electrical device without disassembling it. Use a multimeter or continuity tester to check the appliance's continuityability to pass electricity from one plug prong to the otherwhen the switch is ON. If it passes, the appliance is okay. If not, you'll need to disassemble it further to find the problem. Refer to Testing With a Multimeter for additional tips.