NAD 712 Stereo Receiver display

Question

The LCD display on my NAD 712 receiver quit working. The problem has been isolated to the backlighting for the dispalay (if I shine a flashlight from the backside, the display is visible with valid data). The backlighting consists of two small light bulbs mounted on a small circuit board (1/2" x 1.5"). The bulbs are 4mm in diameter and ~10mm tall (without leads). I measured the voltage supply to these bulbs at 5.5V DC. The bulbs are wired in series. Where can I find a part number and/or supplier for these bulbs? I assume that they must have either a 2.5V or 3.0V rating, but I have not idea regarding current draw. Any suggestions?