Table of Contents
Advertisement
Replace the LCD screen.
Check if display base is well welded. Check if the connection of LCD extension cords
and the CPU is normal. Check if the CPU is welded without tin.
4.Abnormal Operation of TF card
Detection failure of card insertion:
Check if the card connector is damaged and if it is well welded.
Check if power supply of VDD_SD is normal as 3.0V+/-0.1V，if abnormal, please
check PMU circuit.
Check if TF card peripheral components are well welded or if damaged.
5.Abnormal sounds
No sounds of earphone and speaker:
Check U17 related components.
Check if the earphone extension cord is damaged.
Earphone with sounds and speaker no sounds
Check earphone related components.
Abnormal sounds of earphone and speaker
Check U17 related components.
6.WIFI abnormity
WIFI can not scan：
Turn on WIFI， then check if the voltage of VCCIO-WL is normal as 3.3V+/-0.1V， if not,
please check PMU circuit.
Check if welding of WIFI module is good.
Can not detect signal：
Check if antenna plate and feeder are well welded.
7. Camera Abnormity
Run the camera application and then check if related current is normal, if voltage of
VCC28-CIF is 2.8V around. Check if voltage of VCC18-CIF is 1.8V around.
Check if exclusion and camera extension cords are well welded.
8.G-sensor Failure
Check if G-sensor IC is well welded.
9. Button Failure
Check if circuit of the button part is normal. Check if each voltage is normal when
buttons pressed down.
10.Other Failures
A. Large operation current of the system：Check if the main board has heating
components. Test if the power test points of relevant heating components are short
circuited to earth or with small resistance to earth. If yes, replace relevant components.
B. Booting Failure：
Firstly check if PMU related power is normal, if yes, then rewrite img file since the
problem is maybe caused by img file loss. If the device can not boot after rewriting,
probably there is something wrong with the memory.
Advertisement
Table of Contents
