Asus A500KL Schematic
A500KL
EE Trouble Shooting Guide
Fail case 分析
• System can’t power on
• eMMC issue
• Display issue
• Touch Panel issue
Fail case 分析
• System can’t power on
• eMMC issue
• Display issue
• Touch Panel issue
• Camera issue
• USB issue
• Sensor issue
• Audio issue
• Charger
System Can’t Power On
System Can’t Power On
• Step1. 目檢是否有SMT 外觀不良(連錫, 空焊, 偏移, 極性錯誤…………..)
• Step2. 量測以下電壓有無輸出, 有無與GND短路
VREG_S3_1P35V
VREG_L3_1P15V
VREG_S1_1P15V
VREG_S4_2P1V
VREG_L6_1P8V
VREG_L10_1P8V
VREG_L2_1P2V
VREF_LPDDR2;
VREG_L20_3P075V
VREG_L20_3P075V
VREG_L20_3P075V
MSM_RESIN_N
• Step1. 目檢是否有SMT 外觀不良(連錫, 空焊, 偏移, 極性錯誤…………..)
• Step2. 量測以下電壓有無輸出, 有無與GND短路
VREG_S3_1P35V
VREG_L3_1P15V
VREG_S1_1P15V
VREG_S4_2P1V
VREG_L6_1P8V
VREG_L10_1P8V
VREG_L2_1P2V
VREF_LPDDR2;
VREG_L20_3P075V
VREG_L20_3P075V
VREG_L20_3P075V
MSM_RESIN_N
PS_HOLD
VREG_L8_1P8V
VREG_L17_2P95V
VREG_L21_2P75V
VREG_L18_2P95V
VREG_S2_1P05V
• Step3. check 19.2MHZ(X901) frequency 是否正常
• Step4. 照X-Ray檢查PMIC(U2), eMMC(U1401),
SOC(U1) & PoP Memory (U1001)是否有空焊或 是短路
• Step5. Reheat SOC (U301) & PoP Mem(U1001)以確認是否有無空焊
• Step6. update SW image, check 是否SW 沒燒錄好
• Step7. 如果電燈有起，有可能eMMC是空的，須請SW確認是否進入emergency download mode
eMMC issue
• eMMC(U1401)外觀是否有異常，若有異常可視情況換件
• 確認各個power domain供電狀況
– VREG_L17_2P95V 點位 C1404.1 --------------- 2.95V
– VCCQ_EMMC 點位 C1904.1 - --------------1.8V
Display issue
Display issue
• Check LCM 是否有接好
• Check LCM FPC是否損毀
• Check LCM connector (CON1601) 是否有歪斜,破裂,短路或空焊現象
• Check VCC_LCD2V85 點位 C2104.2是否有2.85V(有無對地短路)
• Check LCD_1V8 點位C2109.1是否為1.8V(有無對地短路)
• Check LCM 是否有接好
• Check LCM FPC是否損毀
• Check LCM connector (CON1601) 是否有歪斜,破裂,短路或空焊現象
• Check VCC_LCD2V85 點位 C2104.2是否有2.85V(有無對地短路)
• Check LCD_1V8 點位C2109.1是否為1.8V(有無對地短路)
• Check MIPI 訊號是否正常輸出(0.1V~0.3V)
• Backlight IC (PU8900) 使否有短路或空焊, 極性是否正確
• Check V_LED 點位PC8903.1是否為25.6V(有無對地短路)
• Check LCD_BL_EN點位PSR8901是否為High(3.3V)
• Check LED_PWN_R 點位PSR8902是否有 PWM output or Keep High
• Check P_BL_LX_S的點位PL8900.2是否有 PWM
LCD 線路&點位圖
LEDPWM
CON2101
FPC_CON_33P
112
2
334
4
556
6
778
8
9910
10
111112
12
131314
14
151516
16
171718
18
191920
20
212122
22
232324
24
252526
26
272728
28
292930
30
313132
32
33
33
SIED1
34
SIED2
35
LCD_1V8VCC_LCD2V85 VCC_LCD2V85V_LEDLCD_1V8
MIPI_LCM_CLKN[3]
MIPI_LCM_DP1[3]
MIPI_LCM_DN0 [3]
LCM_ID [4]
LED_FB[89]
RESET_INNO[6]
MIPI_LCM_DN1 [3]
MIPI_LCM_CLKP [3]
MIPI_LCM_DP0[3]
VCC_LCD2V85
C2105
1UF/6.3V
12
V_2P85_EMMC2
R2113
0Ohm
/LCD/
12
C2104
0.1UF/6.3V
1 2
V_1P80_VCCAON
R2114
0Ohm
/LCD/
12
LCD_1V8
VCC_LCD2V85
LCD_1V8
C2109
1UF/6.3V
12
LCD_1V8
LEDPWM
CON2101
FPC_CON_33P
112
2
334
4
556
6
778
8
9910
10
111112
12
131314
14
151516
16
171718
18
191920
20
212122
22
232324
24
252526
26
272728
28
292930
30
313132
32
33
33
SIED1
34
SIED2
35
LCD_1V8VCC_LCD2V85 VCC_LCD2V85V_LEDLCD_1V8
MIPI_LCM_CLKN[3]
MIPI_LCM_DP1[3]
MIPI_LCM_DN0 [3]
LCM_ID [4]
LED_FB[89]
RESET_INNO[6]
MIPI_LCM_DN1 [3]
MIPI_LCM_CLKP [3]
MIPI_LCM_DP0[3]
LCD BL 線路&點位圖
P_BL_OVP_3
30mil
20mil
PC8903
1UF/50V
12
PR8903
560KOHM
1 2
PC8904
1UF/50V
@/Power/
12
PC8905
0.1UF/50V
N/A
12
PC8902
10UF/6.3V
12
PL8900
10UH
PR8904
20KOhm
PD8901
PMEG6010CEH
2 1
PC8900
1UF/50V
12
GND
GND
GND
VSYS
V_LED
GND
GND
2X2
Vih=2V
P_BL_EN_3
P_BL_DIMC_10
P_BL_OVP_3
P_BL_LX_S
P_BL_OVP_3
30mil
P_BL_PWM_3
20mil
PC8903
1UF/50V
12
PR8903
560KOHM
1 2
PC8904
1UF/50V
@/Power/
12
PC8905
0.1UF/50V
N/A
12
PC8906
0.1UF/6.3V
@/Power/
12
PU8900
RT8511BGQW
06087-00070100
OVP
1
FB
2
DIMC
3
GND1
4
GND2
9
EN
8
PWM
7
VIN
6
LX
5
PC8902
10UF/6.3V
12
PL8900
10UH
0201
PSR8901
@
21
PC8901
1UF/6.3V
12
PR8904
20KOhm
1 2
0201
PSR8902
@
21
PD8901
PMEG6010CEH
2 1
PC8900
1UF/50V
12
GND
GND
GND
GND
GND
GND
VSYS
V_LED
VSYS
GND
GND
GND
LED_PWN_R 21
LCD_BL_EN 86
GND
Touch Panel issue
• Check CON1301 是否有破裂,短路或空焊
• Check TP 是否有連接好
• Touch IC (U1301) 是否有短路或空焊,
pin１位置是否正確
• Check D1V8點位R1313電壓準位是否為1.8V
• Check CON1301 是否有破裂,短路或空焊
• Check TP 是否有連接好
• Touch IC (U1301) 是否有短路或空焊,
pin１位置是否正確
• Check D1V8點位R1313電壓準位是否為1.8V
• Check A3V3點位R1304電壓準位為3.3V
• Check I2C_0_SDA, I2C_0_SCL電壓準位是否為1.8V
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