Nokia 6020b Service Manual
RM-31
Nokia Customer Care
7 - System Module
30
COMPANY CONFIDENTIAL
Issue 1 03/2005
Copyright © 2005 Nokia. All Rights Reserved.
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Keypad
The RM-31 keys are connected to the UPP via the KEYB(10:0) bus. The keypad consists of a
5x4 matrix of 5 rows, ROW0 – ROW4, and 4 columns, COL1 – COL4.
5x4 matrix of 5 rows, ROW0 – ROW4, and 4 columns, COL1 – COL4.
Additionally, there are 3 lines that are directly connected to the UPP IO and can be detected
independently. COL5 is connected to GENIO0.
independently. COL5 is connected to GENIO0.
Test possibility
Phoenix Keyboard Test
For troubleshooting, see Keypad faults in Baseband Troubleshooting Instructions.
Figure 10:RM-31 keypad
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Illumination
In RM-31, white LED’s are used for the LCD backlight and keypad lighting. Three LED’s are
used for the LCD lighting and two LED’s for the keyboard. A step up DC-DC converter is used
as a LED driver that is configured as a constant current source.
used for the LCD lighting and two LED’s for the keyboard. A step up DC-DC converter is used
as a LED driver that is configured as a constant current source.