1. The problem statement, all variables and given/known data Four devices are connected in series across a voltage source of 120V. The total circuit current is 4.5A. One device fails to operate. The voltage across each of the other devices is 40V. What circuit fault is indicated and where? 2. Relevant equations E=IR I=E/R R=E/I et al. 3. The attempt at a solution I'm afraid I'm not really sure what the instructor is looking for here. It seems clear to me that one of the devices has shorted out. I wrote for my answer, "One of the devices has shorted out - its resistance has become 0 ohms." That sounds like the circuit fault to me, but where . . . ? Am I missing something here?