Blu Touchbook 7.0 3G, Service Manual, Page: 43 / 45

2) Check all the power related to WIFI and BT are in correct level
3) Check the main chip U1001’s welding is ok
12
）
Trouble 13: MIC has no response
Possible Cause:
1) Check the connect between the main board and small board, if
the fpc is broken
2) Check the MIC, if it is damaged
3) Check the power Micbias0 is in proper level
The follow is main circuit
13
）
Trouble 14: No sound for Speaker
Possible Cause:
1) Check the connect between the main board and small board, if
the fpc is broken
2) Check the Speaker, if it is damaged
3) Measure the power Vbat, if it is existed, and if its level is correct
4) Measure the waveform of C423,if the waveform is ok
5) Check the welding ofU402
6) Check FB413,FB414
The follow is main circuit