Flash Led Troubleshooting; Introduction To Flash Led Troubleshooting; Flash Led And Image Taking Conditions - Nokia n81 Service Manual

RM-179; RM-223
Camera Module Troubleshooting

Flash LED troubleshooting

Introduction to flash LED troubleshooting

A fault or complaint associated to LED flash operation can be roughly categorized into two subgroups:
1 Flash is not functional at all (no light output at all).
2 Images can be taken and they are recognizable but for some reason the quality of images is degraded.
Examples of quality degradations:
• Brightness is not sufficient.
• Brightness is too much = overexposed.
• Only portions of the image brightness (e.g., left, right, top or bottom) are proper and the rest are not.
The quality of an image is very difficult to measure quantitatively, and even comparative measurements are
difficult (comparing two images), if the difference between reference images is small. If a user is not satisfied
with his/her device's image quality, it is fairly difficult to accurately test the device and get an exact result,
which would tell if the device is working properly.
Often subjective evaluation has to be used for finding out if there is something wrong in the flash. Some
training or experience of a correctly operating reference device may be needed in order to detect possible
faults. It is easy for a user to take low quality images in bad conditions. Therefore, the camera and flash
operation has to be always checked in constant conditions (lighting, temperature) or by using a second,
known-to-be good reference device.

Flash LED and image taking conditions

This section describes some of common factors, which may cause poor image quality if not taken into account
by end users when taking pictures, and may therefore result in complaints. The items described are normal
to the camera and LED flash operation and do not raise a need for servicing the components.
Issue 1
Figure 46 Example of a good quality image taken with the flash LED
COMPANY CONFIDENTIAL
Copyright © 2007 Nokia. All rights reserved.
Page 5 –13