Nokia 5510 - Page 81

PAMS Technical Documentation UI Module Troubleshooting
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Keyboard/Hotkey
Malfunction
Side Keys
Malfunction?
Check the
alignment of
domesheet
Ensure there is no
foreign particles on
the keypad
Check if pull-down resistors
R701, R703, R704, R705,
and network resistor R702
are correct and properly
soldered
Check if SW753,
SW754, SW755, SW756
side keys are intact
Are VBAT, VBB
and UC_VCC voltages
correct?
Check B2B
connector and U501
regulator output
voltage(2.8V)
NO YES
NO
YES
Check 32.768kHz
crystal frequency and
MCU. Replace them
if necessary