How do I know whether the memory module on an MPU is damaged or securely inserted on CE series switches

If no memory module is installed on the MPU, the MPU resets repeatedly and the RUN/ALM indicator of the MPU is steady green. Meanwhile, the following information is repeatedly displayed on the console port:
*************************************************************
*  Copyright (C) <2012-2013> Huawei Technologies Co., Ltd.  *
*****************K100********************************************

CloudEngine BIOS Version: 208  (Jul 02 2013 - 13:16:02)
Board Name ..................................... CE-MPUA
Error: invalid primary sdram width!

### ERROR ### Please RESET the board ###

If the memory module on the MPU is damaged or loosens, the MPU resets repeatedly and the RUN/ALM indicator of the MPU is steady green. Meanwhile, the following information is repeatedly displayed on the console port:
*************************************************************
*  Copyright (C) <2012-2013> Huawei Technologies Co., Ltd.  *
*************************************************************

CloudEngine BIOS Version: 208  (Jul 02 2013 - 13:16:02)
Board Name ..................................... CE-MPUA
SDR

When the memory module is working properly, the following information is displayed:
*************************************************************
*  Copyright (C) <2012-2013> Huawei Technologies Co., Ltd.  *
*************************************************************

CloudEngine BIOS Version: 208  (Jul 02 2013 - 13:16:02)
Board Name ..................................... CE-MPUA
SDRAM Memory Size .............................. 4 Gbytes
SDRAM ECC initializing ......................... DONE

Press CTRL+T for full memory test .............. skip