BB training for NKF 02,05, 2015
Function block (BB)
BB Component Placement- MB (Top) G
Power On Sequence
PMIC output
Sleep mode entrance sequence CPU PMIC SLP_S0IX_B
Sleep mode exit sequence CPU PMIC SLP_S0IX_B
BB issues 開機失敗 USB無法辨識 SD無法辨識 KEY 沒反應 前後相機無法開啟 TP不良 耳機或Speaker無聲 MIC無法錄音 G sensor test fail 未插charger,卻出現充電訊號 Slim port 顯示問題
Fail boot check Crystal Select “re-boot” Power on Small current no 電流 Current always keep on a value Crystal Select “re-boot” Power on Small current no Display 電流 Entry Recovery Mode abnormal yes normal Current always keep on a value Big current yes 1.Check IC 2.Check parts whether have short Entry DNX Mode Lack of parts check no CPU/BIOS/DDR/EMMC checkFPC check CPU normal abnormal Confirm LCD Change or replace replace
Example symptom: booting current 0.4A0.04A0.4A cycle EMMC not be complete burnned symptom: booting current 0.04A 0. 4Astop CPU fail
Example Symptom: current keep on 470mA during power off, PMIC have output，LCD can’t display，USB can’t detect Root cause: U3500 ( BIOS) didn’t complete burned.
Example Shielding cover didn’t assemble well，shielding cover was short with parts which will cause device can’t power on.
USB can not identify USB Fail Select “re-boot” Check surface、pin and pad spot of J9400 Entry Recovery Mode abnormal normal Replace J9400 or re-solder abnormal confirm USB Voltage Confrim PMIC (U2003) normal fail confirm USB switch Confirm USB switch whether solder ok? Or IC is defective pass Confrim CS Clock (R1029) confirm CPU (U1000) abnormal normal Confirm USB PHY (U9001)
USB schematics 1 USB Conn USB Switch U9001(USB PHY) J9400 CPU
USB schematics 2 USB PHY CPU USB Switch
Example: can’t identify USB port PMIC(U2003): Pin55,61 and PIN59,60 are short which cause the voltage “+VUSB_CONN_FUSE” to low then USB port can’t be identified.
Ex: charger does not insert, but appear charging icon or charge current is too big . PMIC: Pin55,61與 PIN59,60短路
SD can’t be identified 1.Check the soldering of SD connector 2.measure the path of SD connector 3. Sd identification PIN(SDMMC3_CD_N) have action? With SD : GND ; without : High
KEY no response Confirm KEY FPC Measure all paths PMIC CPU CPU
Front CCD can’t enable abnormal Re-assembly normal normal Defect CCD Front CCD Fail abnormal assembly Re-assembly normal normal replace Defect CCD abnormal Check whether was short Check voltage(V1.8、V2.8) abnormal normal check IMG version Alston Chiu
Front CCD B8012,B8013 location
Rear CCD can’t enable abnormal Re-assembly normal normal Defect CCD Rear CCD Fail abnormal assembly Re-assembly normal normal replace Defect CCD abnormal Check whether was short Check voltage(V1.8、V2.8) abnormal normal check IMG version Alston Chiu
Rear CCD 注意B8010,B8011, B8014零件位置
TP fail Check IMG version Check FPC and Conn Check all parts on TP FPC
Audio jack/speaker/microphone
Earphones was defective Check Audio jack (J7001) 件 MIC right Audio switch left
Earphones was defective Check audio switch是否正常 Check UART_3_DEBUG_SW Audio switch
Earphones was defective Check U7001, R7014, R7015 Audio codec
Can’t identify Earphone Check Audio jack Check JACK_DET Check Audio codec (U7001) JACK_DET MODE High Speaker Low earphone Audio codec (U7001)
EX: no sound during earphone record Root cause: FB7010 was defective Audio codec (U7001) Audio Jack (J7001)
EX: Right channel was no sound 原因: lack of FB7008，CR7004 was shift
EX: Right channel was no sound UART_3_DEBUG_SW didn’t switch “Audio switch” UART_3_DEBUG_SW MODE 1.8V Debug 0V earphone Audio switch
Speaker schematics Check all parts on path of right & left channels Whether Speaker 、connector are defective? Left channel Right channel
EX: speaker no sound Root cause: SH7001 was defective which casuse U7001.46 and U7001.2 have no electricity Audio codec
MIC can’t record Check soldering . Measure whether was short Whether MIC was defective ? Microphone
G sensor fail EX: G sensor verify, X=0, Y= 1.3 ,Z=9.8 , Y was abnormal X-ray check reheat
Slim port display problem 1. Confirm U3100, X6202 2. Confirm the voltage of +V1P8A_slimport, +V3V3_slimport
Thank you for your attention