I, Subhas Bose, would like to inform you that, I am using a Nokia Lumia 520 (Old IMEI no. (removed for privacy reasons), NewIMEI no. (removed for privacy reasons) which has already been repaired from Nokia care (Manasi (818_504886), 22/1, Ashutosh GhoshRoad, Sethpukur, Barasat, West Bengal, 700124, Contact No. 9874436633) for several times. But a new problem has been arisen. The upper red sensor of the phone; which generally blinks at calling time; I found that it is also blinking (in low brightness)when the phone is kept in lock screen condition. But when the phone is not in locked screen condition; it means when I am using the phone for internet;(not for talking) it's not blinking. It's normally glowing when I am calling. But it should not blink even in low brightness in lock screen condition. Why it is happening? What should be done?