Nokia N900 Service Manual

Figure 44 Image of point light sources taken with a clean protective window
Figure 45 Image of point light sources taken with a dirty (finger print) protective window
Faulty pixels in images
Faulty pixels are pixels that do not respond to light in the same way as the pixels around them. There are
three main types of faulty pixels, dead, stuck and hot pixels.
Dead pixels are always black or significantly darker than their surrounding. Dead pixels appear as black spots
in all lightning conditions. Camera modules producing images with dead pixels that are clearly noticeable
should be replaced.
If the pixel remains always saturated to its maximum value it is stuck. Stuck pixels may appear as red, green,
blue or white spots in all lightning conditions. Camera modules producing images with one or more stuck
pixels should be replaced.
Hot pixels are pixels that easily saturate in dim light conditions. It is normal to get a lot of noise and hot
pixels in night conditions or otherwise dark conditions. The hot pixels should disappear when the ambient
light is increased, but may still appear in darker areas of an otherwise well illuminated scene.
When examining an image for defect pixels, test images should be viewed as 100% enlargements on a PC
monitor.
RX-51
Camera Module Troubleshooting
Page 5 –14 COMPANY CONFIDENTIAL Issue 1
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Nokia N900 Specifications

General

RAM	256 MB
Internal Storage	32 GB
Operating System	Maemo 5
Battery	Removable Li-Ion 1320 mAh battery (BL-5J)
Weight	181 g
Network	GSM / HSPA
SIM	Mini-SIM
GPU	PowerVR SGX530
Memory Card slot	microSD, up to 16 GB (dedicated slot)
Loudspeaker	Yes, with stereo speakers
3.5mm jack	Yes
GPS	Yes, with A-GPS; Ovi Maps
Sensors	Accelerometer, proximity, compass
Talk time	Up to 6 h 30 min (2G) / Up to 4 h 30 min (3G)
Display	3.5 inches, 800 x 480 pixels
Processor	TI OMAP 3430
Camera	5 MP
Dimensions	110.9 x 59.8 x 18 mm
Connectivity	Wi-Fi 802.11 b/g, Bluetooth 2.1
Radio	Stereo FM radio
Browser	HTML, Adobe Flash