Kenmore Canister Whispertone 116 - Does not Power On?

The unit appears fine meaning no broken wires, connections, etc. but it does not turn on with or without the powerhead attached - it's dead. I tried the reset on the powerhead and opened the motor chamber to look for anything amiss - no clues. Are there any fuses or other resets? I read that there was a thermal 30 minute automatic reset for motor overheating but since it's been days since it worked, this does not appear to be a factor. This vacuum was used by several of my Dad's caregivers so unfortunately I do not have the details of what happened when it stopped working. It's about 5 years old. Can anyone suggest what the trouble might be?

Thank you for any help you can provide. The vacuum is otherwise in fine shape, so I would really prefer to fix it then buy a new one.