I get that there is a lot of people asking the same question, but not under the same circumstance. The 390, from what I've seen crashes when not being under load. I RMA'd my 390 and sent it to California and while it took 3 months to fix, I bought a 480. But I recently bought a 144 hz monitor that the 480 wasn't compatible with because it didn't have displayport. So when I got the 390, I put the 390 back in. Now they said they fixed it, but occasionally I get a black screen on the monitor that is running the 390 when it's not under load. Before the RMA, games would just crash. But after I played Fallout 4 with v-sync, the card crashes every day. I pushed the card pretty hard while playing fallout 4, but I'm pretty sure I made it unstable again. I raised the power by 25% and sometimes it would just reset it even after it was set to 25%. I'm thinking of just telling MSI for a refund because waiting 3 months for a card that is still faulty is bs.
What I mean by crashing is that before the RMA, it would go blue screen, but after the 390, while under no load, would go black screen and my pc would freeze