User Guide

RH-12/RH-28
Baseband Troubleshooting Instructions CCS Technical Documentation
Page 6 Nokia Corporation Issue 1 02/04
General Failures
Phone is dead
This means that the phone doesn’t use any current at all when supply is connected and/
or power key is pressed.
It is assumed that the voltage supplied is 3,9Vdc. UEME will prevent any functionality at
battery/supply levels below 2,9Vdc and the software will shut the phone down at 3,1Vdc.
Figure 1: Phone is dead
Phone is dead
Measure voltage on L260, L261,
L262, L263, L264, L265 and L206.
Should be ~3,9V
Yes
Failure in VBAT line:
Check X100, L260, L261, L262,
L263, L264, L265, L206, C260,
C261, C262, C283 and pwb
NO
Measure voltages on both sides of
R302 when power key is pressed.
Should be ~0V.
Yes
Check:
R302, S323 (power key) and pwb
NO
Sleep clock on J401:
~32,768kHz, 1,8Vpp
Yes
Check:
B200, C209, C210, D200 and
PWB
NO
Measure voltage on PURX =
1,8Vdc on J404 or N131 pin 3
~1sec after power key is pressed.
Yes
Check:
D200 and pwb
NO
Measure voltage on VR3=2,78Vdc
on C295 pin1
Yes
Check:
D200, C295 and pwb
NO
Verify that system clock is @
~26MHz, min 300mVACpp on
C422 pin2 towards D400 (TIKU)
with regular probe Cin ~10-13pF /
10M
Yes
Check:
C422, R420, C514, C515, L515,
N500 (Helgo), G501 (26MHZ
XTAL) and pwb.
NO
Check:
D400 (TIKU) and D450, D451
(Flashes) and D455 SDRAM
Yes