Training for ALT 10 30, 2014 YJ / Terry

BB Component Placement- MB (Top)

BB Component Placement- MB (Bottom)

BB Component Placement- ANT/B (Top)

BB Component Placement- ANT/B (Bottom)

Function block

Power Sequences

Power on regulator sequencing

BB issue list Can’t power(big current) Can’t enter system No display after display flashs Power off current Fail Can’t charge Can’t recognize USB Can’t recognize SD KEY no function Rear/front camera are fail LCD/TP no function earphone或Speaker no function MIC no function

Can’t power(big current) Check all power planes for shorts to ground or to each other Check Polarity Check whether have the wrong components Check components whether was damaged Check X-Ray

EX1: 238: C1650 was wrong VREG_L17_2P9 then was short with GND.

EX2: 173: U2400 was reverse

EX3: 215: R3102 & C3107 short, B1805 was short).

EX4: 458/374/420/393/256 : Shielding shift short

EX5: 660 : U601 short

EX6: 375 : R605 was air welding

Can’t enter system 469 : U4001 damage

No display after display flashed 233 : R1503 wrong

Power off current Fail 210 : R2410 shortage

Can’t charge(Charger Current Fail)

Can’t recognize USB check USB connector check USB circuit Check Fuse_5V (F2300) Measure per electric meter Use Diode measure (ID、D+ 、D- ) impedance then compare with good board Traces whether was connection Check USB D+ 、D- path B2300 &R1715 & R1716 0R whether was air welding . Check USB_VBUS_IN_PMIC whether have voltage output 4.5V

USB schematics

Can’t recognize SD 1.Check polarity and whether have air wielding 2.use electric meter to make sure the path is connection with connector. 3.insert SD card to measure the related electric current. (R1724 Pu-H 1V8 / VREG_L5_1P8/ VREG_L11_SDC/ VLDO_SD_3V /VREG_L12_SDC) 4. the related current of SD_LDO (VPH_PWR / VREG_L5_1P8/ VREG_L11_SDC)

KEY no function 1.Check polarity and whether have air wielding 2.use electric meter to make sure the path is connection.

Rear/front camera are fail Check U803, U1601, J1600 Check Power : VREG_L10_2P8_AF, VREG_L6_1P8,VREG_L17_2P9, CAM_DVDD-1P Check the back camera was complete to assembly Check the back camera was good.

The circuit of back camera

Front camera was fail Check U802, J1602 Check Power: VREG_L6_1P8,VREG_L17_2P9 Check the front camera was complete to assembly Check the front camera was good.

The circuit of front camera

LCD/TP was fail LCD/TP was fail Check LCD/TP whether are complete to assemble Check whether was caused by raw material Check U1501,U1502,U1500,L1500,J1500 LCD don’t light Check the voltage of VREG_L17_2P9,VREG_L6_1P8,LED+TP Check the voltage of VREG_L16_UIM3

Earphone or Speaker was fail Earphone was fail Check J1800,B1801,B1802,B1803,R1812 Check whether have assembly issue Speaker was fail Check B502,B505,J2000 Check the sub board of J100,J102,B100,B101 Check FPC Check whether Speaker have assembly issue

MIC was fail Main and Sub MIC no sound Check U1800，U100 Main MIC was fail Check J100,U100,R100 of sub board Check FPC Check CDC_MIC_BIAS1whether have voltage Sub MIC was fail Check U1800,R1818 Check the voltage of CDC_MIC_BIAS1

Main MIC test fail Check the rubber on Main MIC Rubber whether was complete cover. Check the Mesh Sub MIC test fail