Interview Guides
You are validating an embedded control board that reads a sensor and reports status to a processor. During bench testing, the board powers on, but the sensor value is unstable and occasionally drops out entirely after a few minutes. You have access to the schematic, a multimeter, an oscilloscope, and the board bring-up notes. The issue appears to be limited to one section of the circuit rather than the whole board.
What circuit knowledge would you apply to diagnose this problem, and how would you work through the board step by step to isolate whether the fault is in power, signal integrity, component selection, or the interface between the sensor and processor?