u/Groundswell17

▲ 14 r/TechHardware+2 crossposts

Dead 9850x3d?

Curious if there's anything I could be missing here. This failure seemed to coincide with a distro and display driver update, so it's introduced some doubts on software vs hardware failure.

  • Motherboard: ASRock B650E PG-ITX WiFi (no BIOS Flashback)
  • BIOS: 4.21 (April 13, 2026) — updated via Instant Flash with 7600 installed
  • CPU: AMD Ryzen 9 9850X3D (failed — currently running Ryzen 5 7600 for troubleshooting)
  • GPU: NVIDIA GeForce RTX 4070 Ti Super
  • RAM: Corsair Vengeance DDR5-6000 2x16GB (CMK32GX5M2B6000Z30), running at 6000 MT/s via EXPO
  • Storage: Samsung 970 EVO Plus 2TB NVMe
  • PSU: Cooler Master V850 SFX Gold ATX3.0, 850W, Full Modular (MPY-8501-SFHAGV-3US)
  • OS: Fedora 44 (kernel 7.0.9-205.fc44.x86_64)

Previous BIOS prior to issue and troubleshooting was 4.03

How long it worked: System was running fine with the 9850X3D for 3+ months. Upgraded from Fedora 43 to 44 on May 24, 2026 — rebooted successfully, used the system normally, then shut down. Hours later, attempted cold boot — completely dead. No POST, no display, no signs of life beyond fans/power.

Previous CPU: Ryzen 5 7600 — boots and runs perfectly in the same board with the same RAM and BIOS.

Troubleshooting performed:

- CMOS clear via jumper (60 seconds)

- BIOS updated to latest (4.21) via Instant Flash using the 7600

- Cleared Secure Boot NVRAM keys from BIOS (using the 7600)

- Loaded UEFI defaults with NVME removed, so OS couldn't write EFI variables during boot

- Deep physical CMOS drain with capacitor bleed (power button held 30 seconds with PSU off and jumper bridged)

- Single RAM stick in A2 slot only

- NVMe SSD removed entirely

- 7-minute cold train wait with blank flash — no POST

- PCI riser/GPU disconnected — motherboard HDMI only

Still no post. Is there any chance that something software related occurred here, or have I pretty well ruled it out?

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u/BigDaddyTrumpy — 13 days ago