I have a Eureka Central

Question

I have a Eureka Central Vac CV1601b. The motor does not stop unless the Unit is unplug from the electrical outlet. Any Idea?.I removed the control unit to check if there was disconnected wires or burnt wires. Everything look normal. The circuit board does not show area that overheated. There seem to be 2 relays. Likely one of the two went bad. What do you think.