Usually bit errors can be easily detected in images, and they are best visible in full resolution images. A good
practice is to use a uniform white test target when analysing these errors. The errors are clearly visible,
colourful sharp dots or lines in camera images. See the following figure.
Figure 78 Bit errors caused by JPEG compression
One type of bit error is a lack of bit depth. In this case, the image is almost totally black under normal
conditions, and only senses something in very highly illuminated environments. Typically this is a contact
problem between the camera module and the phone main PWB. You should check the camera assembly and
connector contacts.
If the fault is in the camera module, bit errors are typically visible only when using some specific image
resolution. For example, in case of a viewfinder fault, the error might exist but is not visible in a full size
image.
Note:
At the most 5 clusters of black dots or blemish are not considered errors, and no reason to
replace camera module
RM-180
Camera Module Troubleshooting
Nokia Customer Care
Issue 1
COMPANY CONFIDENTIAL
Page 8 –13
Copyright © 2006 Nokia. All rights reserved.
