机芯方案:
海思V600
故障现象:
红灯亮,不开机
测量供电正常,无SW、BRI信号,怀疑主板故障。
检修过程:
打印信息如图一所示:
“Boot rom start Boot from emmc Starting fastboot System startup SWD00000001 ERR0000FFF5 ”
本着先简后繁的原则,先写引导,出现如图二所示的提示打印信息为:
“SerialPort has been connencted, Please power off, then power on the device.
If it doesn’t work, please try to repower on.
#####################Failed to send head frame!
Failed to download File!
Failed to download fastboot!
怀疑EMMC不良,更换EMMC用电脑重新写引导仍然不正常。
最终更换主芯片N1(HI3751ARBCV600CMGN ),并写引导,U盘升级后故障排除。
维修总结:遇到主板故障,熟练掌握各机芯各种故障时打印信息,根据打印信息作出相应判断。完善维修记录,对于后期维修起到事半功倍的作用。
故障板号:
RSAG7.820.6854
故障元件:
N1