This brief proposes an electrical method using simple resistor chain in parallel to quickly locate open circuits in a 3-D chip. This method is theoretically analyzed using the equivalent circuit, and experimentally validated by a 3-D integrated circuit (3-D IC). The fabricated 3-D IC consists of one printed circuit board, one organic substrate, and seven 65-nm CMOS dies stacked using microbumps and through-silicon vias. Results show that, the proposed parallel resistor chain can efficiently locate opens in a complicated 3-D IC within several minutes, using the resistance measured by power supply or multimeter only.