Question GPU (maybe PSU?) Problems

Jan 6, 2020
I recently built my first computer, and I went kind of high end with an EVGA rtx 2070 super (the one with LEDs), but about a day after getting everything set up the LEDs on it turned off and wouldn't turn back on. A few weeks later the PC blackscreened and the GPU fans went insane, spinning way too fast, so I reset it and suddenly the LEDs were back on. It then did the blackscreening max-fan thing again, so I opened it up and switched out the cable connecting it to the PSU (it's a modular PSU) and it stopped. Now it seems to be fine, the LEDs are on and it's been an hour without any black screening, but should I still be worried? Is it possible that the problem was that psu cable? I read some other forums with the exact same problem but they seemed to come to the conclusion what caused it was some thermal paste issue on the GPU, not the PSU, so am I safe or should I call the warranty on my graphics card (or should I call the warranty on the power supply?) Thanks in advance.

Oh, and in the event viewer the source is listed as kernel power, which I think means a PSU problem but I'm unsure. Thanks.