Nokia 6090 サービスマニュアル

PAMS

Technical Documentation

NME–3

Troubleshooting

Page 63

Issue 1  10/99

First check with WINTESLA which keys are not working. Then change
keymat and repeat test. If anything is ok keymat was defective otherwise
check connections from MCU to keypad matrix.

If all connections are ok check diodes and pullup resistors for keypress
interrupt. If  ok  change the MCU (D300).

First check which kind of failure you have, is complete keypad and/or
LCD illumination not working or only a part of the illumination not working.

If complete keypad illumination is not working measure voltage at base
(Pin2/V422). If voltage is approximately 4.4V then change V422, if not
change MCU D300.

If complete LCD illumination is not working measure voltage at base
(Pin2/V423). If voltage is approximately 4.4V then change V423, if not
change MCU D300.

If only one part of the keypad or LCD illumination is not working check the
3 diodes of the common part.

For checking the hall sensor connect the handset to an radiounit and con-
nect this equipment to an powersupply and an CMD55. Setup a call. Then
check the handset and the handsfree mode via the cradle. If the audio
switch handset/handsfree is working then change the cradle.Also  check
the level at the hallsensor output N400 is low when the handset is in the
cradle. If not change the hallsensor. Is the hallsensor working then
change the MCU D300.

When the power key is not working first check the curly cord. If curly cord
is ok change power key button else check the  passive hardware circuit.