I got 70mai Smart dash cam pro today. not installed in car yet. just checking the setup but   

it's recording black screen and when i try to open the Video file both in cam and on the Laptop via a card reader. It says the video file is corrupt.

Basically in short term, I think the camera is recording but the image is nor capturing. any suggestions is it a known problem or hardware malfunction?

But i do notice on the first bootup camera worked before installing the SD card. 

I used Sandisk 64GB class 10 brand new memory card for it. later in order to verify it's not a memory card issue. i used 32GB Class 10 card from my cell phone. but still, the issue persists mentioned above.