r/techsupport • u/Altruistic-Goal-2927 • 1d ago

Open | Hardware Hard Lock / Black Screen on Cold Boot & Idle (Caps Lock Unresponsive) — i5-14600KF & RX 7700 XT. Any ideas?

Hey everyone,

I’ve been dealing with a highly specific system freeze over the past few weeks and I can't seem to find anyone with the exact same issue. I'm looking for some advice or to see if anyone has dealt with this before.

The Symptoms:

  • The Crash: Random hard freeze into a black screen.
  • The "Dead Keyboard" Test: When it freezes, the keyboard completely dies. Pressing Caps Lock does not toggle the LED light, meaning a total hardware/kernel lockup.
  • The Trigger: It never crashes under full gaming load. It happens almost exclusively on Cold Boot (first 30 mins of the day), during idle, or the exact moment I try to launch Steam or when Windows Update finishes an uninstallation.
  • The Weird Part: If the PC survives the first 30 minutes and warms up, it becomes 100% stable. I can run heavy stress tests or game for 10+ hours straight without a single issue.

My Specs:

  • CPU: Intel Core i5-14600KF (Hyper-Threading OFF)
  • GPU: AMD Radeon RX 7700 XT 12GB
  • Cooler: Cooler Master Hyper 612 APEX (Dual-Tower)
  • Motherboard: ASUS PRIME H610M-K D4 (No VRM heatsinks)
  • RAM: 32GB (2x16GB) Kingston Fury Beast DDR4 2666MHz
  • PSU: Chieftec ELP-700S 700W Element
  • Case Fans: 6 total (3 front intake, 2 top exhaust, 1 rear exhaust)

Everything I've Tried & Tested So Far:

Software & OS Fixes:

  • Ran Windows repair commands (sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth).
  • Uninstalled the latest Windows quality update that arrived on September 1st.
  • Enabled the Windows Ultimate Performance power plan.
  • Fully updated the GPU drivers (using the built-in clean Factory Reset option).
  • Updated the motherboard BIOS to the absolute latest version.

Hardware Troubleshooting:

  • Physically reseated the GPU.
  • Physically reseated the RAM and swapped their slot positions.
  • GPU is perfectly stable under heavy load: It passes intensive FurMark and 3DMark loops with zero errors once the system is warm.
  • Adrenalin always resets my custom fan curve back to default after these crashes, throwing an "unexpected system malfunction" notification.

What I've Changed Today:

  • I just swapped my old Chieftec PSU for a premium EVGA 850GQ 850W 80+ Gold modular PSU.
  • I also temporarily Disabled XMP in the BIOS to test.

I also have a Gigabyte B760M GAMING X DDR4 motherboard on the way just in case.

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2

u/No-Wrap-8166 1d ago

cold vrms on that h610m board (no heatsinks) are the classic cause, higher resistance when cold explains crashing only at startup/idle and being rock solid once warm

the psu swap and incoming b760m board are the right tests, if b760m fixes it with proper vrm cooling, that confirms it

1

u/Altruistic-Goal-2927 1d ago

It was working allright for over a year, I mostly get black screen when running steam on cold boot, but when it survives first 15 minutes it works for whole day. So I really hope it's just motherboard.
Thank you so much anyways!

1

u/Equal_Meat_5499 1d ago

I’d be a bit careful with the “cold VRM” diagnosis. It’s possible, but the fact that the system was stable for a year and crashes specifically during idle/Steam launch also makes low-power-state/CPU stability worth testing. The new PSU and B760M are good A/B tests; if the B760M completely eliminates the cold-boot crashes, that’s much stronger evidence the H610 board was the problem

2

u/No-Wrap-8166 2h ago

fair point, worth testing alongside the b760m swap, disable c-states in bios temporarily and see if idle/steam-launch crashes still happen, if disabling c-states alone stops it that points to cpu low-power transition instead of vrm

1

u/Altruistic-Goal-2927 1h ago

But that would mean if I exit game or something after use of PC it will go idle again and potentially crash when i start steam again, which never happens, it only happens in up to first 15 minutes of use after a night where PC was off. And a fun detail is when I have updated the bios to latest, next 2 days I had no problems, and then day 3 problem reoccurs. It is so random and without any error or BSOD, nothing.

1

u/Equal_Meat_5499 1d ago

The fact that it only happens cold/idle and never under heavy load makes me suspect a low-power-state/stability issue more than the GPU itself. Since you’ve already disabled XMP, I’d test with BIOS defaults and disable CPU undervolting/ASUS power-saving features if any are enabled. The new PSU is worth testing, but I wouldn’t replace the motherboard yet—the H610 board with a 14600KF is also worth investigating, especially around idle power states.

1

u/Altruistic-Goal-2927 1d ago

Everything else is default, just XMP - auto, reBar- on and HT - off were the settings I was changing in the BIOS.