New GPU doesn't work

[Pursuit]

I recently purchased a used Galax RTX 3070 from the Zoukart Facebook Marketplace group, however I experienced a problem. It worked properly for one day after installation. After shutting down and trying to restart, my computer failed to boot, with no lights or sound. However, unplugging the PCIe cable caused the machine to boot normally, but the GPU fans did not spin. The seller suggested that something caused a short to the gpu, and suggested it might be the psu, then I replaced my power supply. So I got a replacement because the seller promised a 30-day guarantee, and the same thing happened: the GPU worked on the first and second boot. However, following the second boot, the computer did not restart.And this time, I had to remove either the pcie cable or the GPU.Both times When I turned the machine back on, I heard a strange click coming from the power supply. This time, the seller stated that the short might be caused by the motherboard. But when I put my old Zotac 1050 Ti back in, it works well. Could someone please explain what's wrong with the GPU? Following this, the seller disputed the warranty and stated that even if he provided a third card, it would simply die. I also noticed that the ground from the power board where I plug in my computer is not working, although this has never caused a problem with my 1050 ti before. Specs: CPU: Ryzen 5 5600G Motherboard: MSI B450M PRO VDH-MAX RAM: Corsair Vengeance 8GBx2 DDR4 3200MHz PSU (Old): Corsair CV 450 PSU (New): MSI MAG A850GL PCIE5 GPU (Old): GTX 1050 Ti GPU (New): GALAX RTX 3070

[Chree]

what power supply did u have it  up to for a whole day?

 

[Pursuit]

I had a MSI MAG A850GL