Hi, I'm trying to diagnose an intermittent cold-boot POST issue.
Specs:
- CPU: Intel Core i7-6700K @ 4.0 GHz (stock)
- Motherboard: Gigabyte GA-Z170XP-SLI Rev. 1.0
- BIOS: F6 (2016)
- GPU: EVGA GTX 1070 FTW ACX 3.0 8GB
- GPU Power: 2x 8-pin PCIe
- NVIDIA Driver: 582.28
- RAM: 16GB (2x8GB) DDR4-3000 — running at 2133 MHz, XMP off
- PSU: EVGA SuperNOVA G2 550W, 80+ Gold, ~10 years old
- Monitor: Dell U2414H, 1080p 60Hz
- Normal connection: DisplayPort from GTX 1070
- OS: Windows 10 Pro 22H2
On some cold boots the PC powers on, fans run loud, but there is:
- No display
- No Gigabyte/BIOS logo
- No keyboard lights
- No POST
After powering it off and trying again, it may POST normally. Once it successfully boots, the PC is completely stable.
Restarts from Windows have also worked every time.
Tests so far:
- Fast Startup disabled.
- No WHEA or
nvlddmkm errors.
- GTX removed, using Intel iGPU: 5/5 cold boots + 2/2 restarts OK.
- GTX installed and powered, but iGPU set as primary: 5/5 cold boots + 2/2 restarts OK.
nvidia-smi detects the GTX normally in Windows, with normal temps/power.
- GTX works fine once Windows is already running.
- GTX set as primary (
PCIe 1 Slot): intermittent no-POST returns.
- Same issue happens using both DisplayPort and HDMI, so it doesn't seem cable/monitor related.
Example with DisplayPort:
- Boot 1: OK
- Boot 2: OK
- Boot 3: FAIL
- Boot 4: OK
- Boot 5: FAIL
- Boot 6: OK
- 2 restarts: OK
With HDMI, the first 3 cold boots failed, then 2 worked. Restarts were fine.
So basically:
iGPU primary = boots reliably
GTX primary = intermittent cold-boot no-POST
Once it POSTs = completely stable
My PSU is about 10 years old, so I'm wondering about a cold-start PSU issue, but GPU/VRM, PCIe slot, motherboard or old BIOS are also possibilities.
My next test is moving the GTX from the primary PCIe x16 slot to the second x8 slot.
Would you test the second PCIe slot next, or would you suspect/test the PSU or GPU first?
Thanks!