机芯方案：MSD6A648
故障现象：开机5分钟左右死机
测量DC-DC LDO是否异常，无异常，U盘升级主程序未能排除故障，用串口工具观察打印信息分析；打印信心如下：
MIU0_DQS-OK
BIST0-OK
BIST1-OK
#_m
armfwNOTICE: BL3-1: v1.1(debug):e9dbd72
NOTICE: BL3-1: Built : 14:07:05, Mar 18 2017
XU?andled Exception in EL3.
x30 = 0x000000003de2a004
x0 = 0x0000000033000097
x1 = 0x000000001f201300
x2 = 0x00000000000000c5
x3 = 0x0000000000000002
x4 = 0x0000000000000000
x5 = 0x000000003de34548
x6 = 0x0000000000000000
x7 = 0x00000000a0000000
x8 = 0x000000000000ffff
上述打印信息为EMMC损坏，元件型号H26M41204HPR,位号N56
主板 RSAG7.820.9250