Do you have a volt meter?

With the machine off & unplugged, and the heater unplugged from the motherboard, start by measuring the heater element to see if it is still intact. Measure the ohms across the heater. If it's burned out the ohms reading should be open or millions of ohms. It should measure around 5 to 20 ohms if it is still good. Compare it to the other 9 you have.

Is the CR10 a 12V or a 24V printer? Measure your power supply voltage output to make sure it is putting out the voltage it should be.