B550 board, 3070, 750W unit, all of it about eight months old. If the machine has been off overnight the fans spin up, the debug LED parks on VGA and there's no signal on any port. A restart from that state doesn't help, but pulling the card and pushing it back in works every time and then it's fine all day. Integrated graphics on the same board displays normally when the card is out.
Check Above 4G Decoding and Resizable BAR in the BIOS. Both on or both off, never one of each. Half configured is a known way to get a VGA debug light on some boards, and it tends to show on a cold start because that's when the board rebuilds its device map instead of restoring it.
Don't rule out the PSU. After eight hours off the bulk capacitors are fully drained and the 12V rail has to ramp from nothing, which is the hardest thing it ever does. If it's been off twenty minutes it starts easier, which matches what you're seeing.
Timing. Leave it off for 30 minutes and try, then off for eight hours and try. If 30 minutes is always fine and overnight is always broken, that's a cold start supply pattern. If it fails at both, go back to the slot.
How would you separate that from the slot contact theory without buying a second PSU?
Move it to the second x16 slot for a week even if it drops to x4. It costs you a few percent in games and it definitively answers whether it's the slot or the card.
@gasket_goblin · 4mo ago · 3 replies
Cold boot only, fixed by reseating, that's contact. Two things to do in the same session: wipe the gold fingers with 99% isopropyl on a lint free cloth until the cloth comes away clean, and then support the card. A 1.3kg card hanging off the bracket with nothing under the far end levers the top edge of the fingers out of the slot, and metal contracting overnight is enough to finish the job.
A $6 support bracket or even a stack of foam under the end of the card for a week will tell you whether that's it.
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@sawdust_pete · 4mo ago
There is a visible droop, maybe 4mm at the far end. Propping it up tonight.
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@gasket_goblin · 4mo ago
While you're in there, make sure the card has two separate PCIe cables from the PSU and not one cable with a daisy chained second connector. That won't cause your symptom on its own but it makes every other symptom worse.
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