A light assembly for a hand-held medical diagnostic instrument. The light assembly includes a substrate having a top surface and a bottom surface, a light source mounted to the top surface, and the bottom surface having first and second electrical terminals. The light assembly further includes a circuit board disposed inclined to the substrate, the circuit board having first and second electrical terminals, a first connector mounting and electrically connecting the first electrical terminal of the substrate to the first electrical terminal of the circuit board, a second connector mounting and electrically connecting the second electrical terminal of the substrate to the second electrical terminal of the circuit board, a heat sink, and a thermal conductor thermally connecting at least one of the first and second electrical terminals of the substrate to the heat sink.