Fail to burn the OS and SDK using SDK Manager

Dear Sir,
1.I have only installed JP4.3
2.By burning “nv-jetson-nano-sd-card-imager-r32.4.2.zip” to SK card, this version of OS has some very strange problems in use:
a. For example, the TensorRT version system cannot be recognized ( Tried Deepstream sample deepstream_test_1.py but failed ) , there are more questions, please refer to my earlier questions.
b. On a new system, using SDK Manager to install the SDK also has problems.
c. This is why I used the SDK Manager and re-burned together with the OS. I did not expect that the problem is more serious now, which makes it impossible to boot at all.

Is there a flaw in the hardware system itself?