Heat sink

Sensors are located on first and second regions of a heat sink, with a portion of the heat sink interposed between the first and second region sensors. The heat sink is connected to a component by an attachment that conducts heat from the component to the heat sink, and a third sensor is located on the component or the attachment with a portion of the attachment disposed between the third sensor and the first and second heat sink region sensors. Temperature readings from the sensors are compared to identify a failing one of the heat sink, the attachment portion, and the component with respect to heat conduction, which includes identifying the interposed heat sink portion as failing in response to a divergence between temperature inputs from the first and second heat sink region sensors. Rate-of-rise temperature readings may also be observed and compared, including to historical values.