Hey, so I recently bought a rtx 3070 from a reseller, he had used the card for mining but said it worked normally for gaming. But, when I got home and installed it into my computer my main monitor was black but was detected. My second monitor worked fine as it is a 60hz monitor. I updated drivers and checked if the main monitor was recognized and it showed up like it was working, but still a black screen. So I decided to check nvidia control panel and turned down the refresh rate on my main monitor to 100hz which allowed for the screen to be seen for seconds but flickers black each 2 seconds. So I changed it down to 60hz and it seemed to fix it. The screen was stable and didn’t flicker at that hz. I’ve checked the GPU on GPU-Z and everything looked good as far as I know. I also tried to play youtube videos, but it plays for 1 second and just stops, which is not my internet as everything else works perfectly fine. I also tried to switch the port the display port goes in and it doesn’t seem to fix it. I don’t believe it is the cable either as it works perfectly fine on my gtx 1080. I have also not tried gaming on it yet as I have a 500w psu and don’t want to risk messing up my computer as the recommended psu is 650w I believe. Also I’m not sure if it could be just the psu problem but Im getting a new psu on Wednesday which hopefully fixes the problem.