Trouble Shooting - Sharp LC55UB30U Service Manual

Chapter 9
C ' T ON
OULDN T URN
Input Power good?
MB DC/DC is good
Log output
MEMC is work?
END
CONFIDENTIAL – DO NOT COPY

Trouble shooting

Start
Yes
Yes
Yes
N0
1. Check JP2 Pin1&2&3(PWR_5V)
2. Check JP2 Pin10&11(PWR_12V)
3. Check JP3 Pin1&2&(PWR_12V )
1. Check L59 ( 3V3SB)
2. Check L10 (DVDD33)
3. Check R74 be High(12V_POWER ON)
4. Check L31 (DDR Power)
5. Check U20 Pin 4 (SDRAM Terminators Power)
N0
6. Check L26 (DDR Power)
7. Check U21 Pin 4 (SDRAM Terminators Power)
8. Check L12/L13(CPU Power)
9. Check L17/L18/L19/L21 (Core Power)
10.Check L46(VCC1.8V)
N0
1. Check Q27 (Reset IC)
2. Check U35 (eMMC)
3. Check DDR
1. Check MEMC DC/DC
a.Check CE1(MEMC_5V)
b.Check L7(MEMC_3.3V)
N0
c.Check CE5(MEMC_Core_1.15V)
d.Check L5(MEMC_1.5V)
e.Check U7 Pin4(MEMC_0.75V)
2. Check MEMC Reset Q11
3. Check MEMC Flash U39
4. Check MEMC DDR
Power BD fail
Main BD fail
Main BD fail
MEMC fail
Page 9-1
File No. SG-0000361