In my experience with the pine64 it would run for 10 to 15 minutes with screen and then suddenly go black while the pine kept on working. After changing the HDMI cable I had no more problems. Did you try different HDMI cables?
I have one of the best HDMI cables available, it works with all other screen I have, but I will try a different one.
Additionally, I have this red led on the board that does not go out. Why is it on? what could be the error here? I have placed the wifi module correctly, put in the microsd and plugged mouse and keyboard in the usb and connected the power with the accompanying PINE power plug. This is how it should work right?
Problem resolved (HDMI output)
Tried some lower quality cables and HDMI worked.
Retried my high quality cables and they worked after pushing in harder (seemed initially were fully inserted but actually were not fully inserted and were caught on some aspect of the HDMI port).