Figure 9-32 Troubleshooting Process For No Lcd Display; Table 9-4 Description Of The Signals In The Circuit Diagram In This Section; Table 9-8 Description Of The Signals In The Circuit Diagram In This Section - Huawei U8815 Maintenance Manual

U8815
Maintenance Manual

Figure 9-32 Troubleshooting process for no LCD display

Table 9-8 describes the signals in the circuit diagram in this section.

Table 9-8 Description of the signals in the circuit diagram in this section

Signal
VREG_L12_2P85
VREG_S3
MIPI_DSI_LANE2_P
MIPI_DSI_LANE2_N
MIPI_DSI_LANE1_P
MIPI_DSI_LANE1_P
LCD_RST
Issue 1.0 (2012-02-13)
No LCD display.
Is the LCD
normal after the software is
reloaded?
N
Is the backlight available?
Y
Is U910 well soldered?
Y
Is the
J1201connector properly
soldered?
Y
Return the handset to the
factory for repair.
Description
LCD analog voltage
I/O connector digital voltage
Differential signal+
Differential signal-
Differential signal+
Differential signal-
LCD power-on reset signal
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9 Principles and Failure Analysis
Y
End
N
Check L1201 and U1201.
N
Re-solder U910.
N
Repair J1201.
Reference Measurement or
Wave Form
2.85
1.8
1.8
1.8
1.8
1.8
1.8
47