Energy Management Troubleshooting - Nokia NEM-4 Series Troubleshooting Instructions

NEM-4
BB Troubleshooting

Energy management Troubleshooting

Device does not stay on
If the device is switched off without any visible reason, there may be problems in the fol-
lowing areas:
• UEM watchdog problem (WD is not updated by SW)
• BSI line problem (BSI line is floating => contact failure)
• Battery line problem
• Soldering problem
The most likely reason is UEM WD (watchdog), which turns the device off after about 32
seconds if SW is jammed.
This may caused by SW problem, UPP_WD2 problem (Not server by SW), UEM or memory
malfunctions.
The following tests are recommended:
• General power checking
• Clocks
• Memory testing
• Serial Interface
If there is something wrong in BSI line, the device seems to be dead after the power key
is pressed. However the regulators of the device are on a few seconds before the power-
down.
This mode can easily be detected from the current consumption of the device. After a
few seconds the current consumption drops almost to 0 mA.
In this case check component or soldering
• Battery connector X381
EMI-filter R385
UEM D190 (pin number C2)
If phone boots to TEST or LOCAL mode with normal battery, BSI is short circuited to
ground. Check EMI-filter and filtering capacitors, which are located to BSI.
Page 6(a)-14
Company Confidential
Copyright  2003 Nokia Corporation
Company Confidential
CCS Technical Documentation
Issue 1 09/2003