Huawei MediaPad 7 Lite S7-931w - Startup Failure Due to High Current

MediaPad 7 Lite Maintenance Manual
INTERNAL
2012-10-08
Huawei Confidential
Page 37 of 82
External interfaces
No.
Interface Type
Physical
Connection
Mode
Number of
Interfaces
Description
1
USB
Micro-usb
1
It meets the USB 2.0
specification and is used to
connect related devices such
as the PC.
The input is the 5 V/2 A DC
power interface.
2
WCDMA
Main antenna
1
It is used to transmit uplink
voice data (WCDMA).
3
WLAN
Built-in antenna
2
It is used to connect local
WLAN devices.
5
Power key
Dome key
1
It is used to power on or off
MediaPad 7 Lite.
9
Key
Volume
adjustment key
2
VOL+ and VOL-
10
Touchscreen
I2C interface
1
Capacitively compatible
11
LCD
RGB
1
1024 x 600 pixels
12
MHL interface
Micro-USB
1
HD television interface and
USB interface reuse
13
Pog PIN
interface
Pedestal
1
The pedestal is used for
serial port communication
and charge.
9.2 Startup Failure
MediaPad 7 Lite can be normally started only when the following conditions are met:

Press the power key for 2 seconds when the battery is installed.

The battery is installed, the USB interface is connected to the 5 V DC regulated power
supply, and MediaPad 7 Lite is started and enters the USB charge mode.

The battery is installed, the pedestal interface is connected to the 5 V DC regulated
power supply, and MediaPad 7 Lite is started and enters the charge mode.
9.2.1 Startup Failure Due to High Current
Adjust the voltage of the DC regulated power supply to 5 V/3 A. Use the DC regulated power
supply to power the LITE_USB interface. The current exceeds 500 mA after MediaPad 7 Lite
is powered on. This usually occurs when the IC patch is abnormal or damaged.