TB-707A and TB-709A Service Manual

   TB-707A and TB-709A Service Manual

microphone  TF card  earphone  Reset

Power on  USB socket  DC socket  key

 

 WIFI antenna

   Audio codec

  Clock IC  NAND flash  DRRII

  Audio amplifier  Touch IC  Cipher IC  Microchip

  G-Senser   

  U8  VCCA  backlight 

  Battery  WIFI module  T3.3V  3V  1.8v

 Charge IC  wifi 3.3v  TP socket  T10.2V  LCD socket  1.4v 

   TROUBLE  SHOOTING

Device can not power on

End

Please press short power on button

Could not power on

  YES 

 

   NO 

Please plug in DC adapter

End

  YES 

 

 

  NO

Check charge IC

NO DC, Check battery voltage 3.5-4.2V

   NO

 

  YES

If one voltage is fail, please replace it

Check main voltage 1.8v, 3.0v, 1.4v

 

  NO 

 

  YES

If one is problem, please replace it

Check Y2 and U39 pin3 is low lever

 

  NO 

 

  YES 

Please refer to upgrade step and upgrade SW

   

  Upgrade  fail

If failed to upgrade the FW. please remove the battery, then connect USB cable with computer, please short-circuit current of any two parts of NAND FLASH (like 29-30 or 41-42), and try to upgrade the software again follow above upgrading method. ЎЈ

 

 Device do not touch pannle

End

Check touch socket or plug in touch FPC repeat

Do not touch

   YES

 

 

  NO

Check touch IC pin 13 lever ЧЄ»» when touch panle  or plug in touch FPC repeat

 

 

   NO

Touch IC or touch panle is fail

 

Do not connect wireless internet

Do not connect wireless internet

Check wifi 3.3v

 

 

  NO

Check wifi module or antenna

Check voltage of U8 pin4  is 5V and pin 1 lever is 3v

 

Replace U8 or L15

   

 

  NO  NO

Replace module or antenna

 

 

please pay more attention to the antenna place. End of the antenna cannot be with metal material.

 

 Key do not respond

any key terminal is short, lever is o voltage

Check voltage of any key terminal

Key do not respond

 

  YES 

 

 

Please clear key with alcohol liquid Јand install the key again

Check U13 pin5 AVCC and L6 , to see if the voltage is correct

  YES  YES

 

  YES

If no, please use new ones to replace

 

Speaker without sound

Knocking audio amplifier pin 4 , listen if the speak with sounds or not

Please check audio amplifier or speaker

Speaker without sound coming out

  NO

 

 

  YES  NO

Please check if with the earphone,	Please check Audio codec is correct or not.	If one is problem, please replace it

 

  YES   

 

 

  YES

Check U13 pin5 AVCC and L5, if the voltage is correct

 

If not,  please change to the right one.

   NO

 

  NO

If not, please change to the right one.

 

Do not display or display bad