C903
1228-1147 rev. 1
TROUBLESHOOTING
Display Illumination Problems
T
R
O
UBL
ESHOOT
ING
- Opto Sensor Problems
START
Step 1:
Flash the Phone with EMMA SUCR SW
If successful claim SW Flash
If not go to step 2.
Step 2:
Load ETS SW into the Phone
Use TRS Fixture
Use TRS Fixture Display Holder and Connect:
Main Flex Assy, Navigation PBA Assy and Display to the PBA
Connect: VBATT and DCIO/SEPI
Use Fault Trace SW and go to:
MMI
Misc
Init Screen Testing
Led and Backlight
Activate:
Display Backlight
If Display Backlight is working on the TRS Fixture then Replace
Display, Main Flex Assy or Navigation PBA Assy
If not continue with the
Display illumination Problems TRS guide
1:
Use Fault trace SW and go to:
MMI
Misc
Init Screen Testing
Led and Backlight
Deactivate:
Display Backlight
2:
Disconnect the Main Flex Assy and remove
the Display Holder from the TRS Fixture
3.7V - 3.8V DC
at MP 25 (TP4200)
No
Fault trace SW
MMI
Misc
Init Screen Testing
Led and Backlight
Activate:
Display Backlight
17V - 20V
Pk-Pk Pulses
at MP 25 (TP4200)
Shortly after the Display
Backlight has been
Activated
3.7V - 3.8V DC at
MP 57 (N4201_Pin 3)
Yes
Replace
L4200
No
SL 4 Replace
N4201
SL 5 Replace
L4201
Yes
0 Volt DC at
MP 26 (TP4201) and
MP 20 (TP4202)
Yes
Replace
N4201
Yes
SL 5 Replace
N2000
SL 4 Escalate
No
Fault trace SW
MMI
Misc
Init Screen Testing
Led and Backlight
1: Deactivate:
Display Backlight
2: Activate:
Display Backlight
No
More
than 4 Volt Pk-Pk
Pulses at MP 58 (N4201_Pin1)
Shortly after the Display
Backlight has been
activated
Replace
X4202
Yes
SL 4 Replace
V4200
SL 5 Replace
N2000
No
Display Illumination Problems
START
Step 1:
Replace Main Flex Assy and retest the Phone
If successful claim Main Flex Assy
if not go to step 2.
Step 2:
Replace Navigation PBA Assy and retest the Phone
If successful claim Navigation PBA Assy
If not go to step 3.
Step 3:
Replace Display and retest the Phone
If successful claim Display
if not continue with the
Opto Sense Problems TRS guide
Is the
Display
illumination (LEDs)
Ok
Go to
Display illumination
Problems TRS guide
No
Can you see
any picture/image in
the Display
Yes
Go to
Dispaly Problems
TRS guide
No
Use TRS Fixture
Connect: VBATT and DCIO/SEPI
Yes
1.8V – 2.3V
Pk-Pk Pulses at
MP 107 (R2250 OPTO_EN)
Shortly after phone
Power On
SL 5 Replace
N2000
SL 4 Escalate
No
Yes
3V – 3.5V
Pk-Pk Pulses at
MP 37 (TP2203 VOPTO30)
Shortly after phone
Power On
No
Replace
N2210
Replace
X4202
Yes
Is the
Opto Sensor Problem
solved
Claim Component
X4202
No
Yes
SL 5 Replace
N2000
SL 4 Escalate
Opto Sense Problems
SEMC Troubleshooting Manual
11
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