首先检查主板上是否存在缺件或元器件损坏，经仔细检查，没有发现缺件或元器件 脱落；通电检测，CPU、内核供电、晶振、总线电压均正常，没有发现异常；连接串口小板，查看打印信息如下：
Hello world, 299o!{uni}[WEI]
svn:d53c89b169d6802d (Nov 17 2016 13:09:15)
flash_type = 2, secure_type = 0
res=100
b8062204=10000
[kick watchdog]
尝试重新烧写引导程序失败，结果如下：
Connecting..
Connected!
Preparing Enviroment…
Prepare Enviroment: script-Loading, wait for a moment…
Prepare Enviroment: script-Loading, wait for a moment…
Burning to Flash…
Prepare Enviroment: script-Loading, wait for a moment…
Prepare Enviroment: script-Loading, wait for a moment…
Burning to Flash…
DDR:CRC32 Error!
Prepare Enviroment error!
Burn Error: not success!
通过此信息判断主芯片与DDR的通讯存在问题,用万用表二极管档位测主芯片与DDR之间的排组未发现问题，于是更换DDR。更换之后试机故障修复