What was found
RT MAIN LANDING GEAR LIGHT NOT ILLUMINATED WHEN GEAR CONTROL SELECTED DOWN ON APPROACH TO PHX, EMERGENCY GEAR EXTENSION SYSTEM ACTIVATED. TROUBLESHOT SYSTEM FOUND RT MLG INDICATOR BULB NOT ILLUMINATING. REMOVED AND REPLACED BULB, RETRACTED AND EXTENDED LANDING GEAR SEVERAL TIMES. PURGED LANDING GEAR HYDRAULIC SYSTEM, SERVICED NITROGEN BOTTLE AND HYDRAULIC RESERVOIR, ALL WORK DONE IAW 560 MM CHAPTER 32-30-00.