机型：55C68 机芯：S48CT05
故障现象：灯亮不开机
维修与分析：
通电接串口打印信息显示 IBCODE:Utopia LIBVER:2.1554359040 BUILDHASH:
BUILDDATE:2019040414HDMITxRegister[Utopia][SYS]: Function = SYSOpen, Line =
1215,
current resource pri_shm content is: 0
[Utopia][SYS]: Function = SYSOpen, Line = 1234, [SYS INFO] OPEN INSTANCE…
create instance at 2ACF16B0 with private size 128 bytes at 2ACF1700
[Utopia][MIU]:
[MIU INFO] miu opencreate instance at 2ACF1788 with private size 104 bytes at
2ACF17D8
[WDT]Is WDT reset ? 0
[WDT]close WDT in MstarSysInit!
create instance at 2ACF1848 with private size 60 bytes at 2ACF1898
uboot held at [2AADDF60~2BD00000],size=012220A0
DRAM: 189 MiB
Now running in RAM – U-Boot at: 2B300000
eMMC: HS400 200MHz
eMMC 14.67 GB [1D59FF8h]
﨏 RC Check OPEN: 1
set ddr power to low
0x8389
Power Down从打印信息判断从待机到正常开机后再回到待机，由于 55C68是双排线主板，TCON板做在主板上，用万用表量主板上 TCON板部分有短路现象，导致开机以后又待机，Q1001A脱开，开机正常灰屏，更换Q1001A,量 Q1001后短路，查后面跟 12V有关电路发现当脱开电容CT68后阻值恢复正常，更换CT68,开机量 DT2 15V, TDT1 28V升压正常，上机图像声音正常，故障排除。