Hi everyone,

I'm hoping to get some fresh eyes on a persistent boot issue I've been troubleshooting for a while now. I'm completely stuck, as my server fails at the very earliest stages of the Unraid boot process, and I feel like I've exhausted all the common solutions.

How It Happen
My Unraid server was working perfectly until I shut it down to install a new 10 Gbps PCI network card to upgrade its network speed. After installing the card and restarting the PC, it fails to boot, and I have been unable to successfully start the system since.

The Problem

When booting, the server will consistently freeze at one of three points:

1. During the initial file verification (e.g., Verifying bzimage checksum ..., Verifying bzmodules checksum ...)

2. Immediately after loading the kernel (...loading /bzroot ok), at which point the screen freezes or goes blank before any Unraid console text appears.

3. The select screen of what type of Unraid to boot. (The screen where GUI / Safemode / Safemode with GUI is presented.)

This happens with a completely fresh, vanilla installation of Unraid.

Exhaustive Troubleshooting Steps Performed

I've tried to be as methodical as possible. Here is everything I've done so far:

1. Software & Configuration:

• Fresh Install: I have completely wiped my USB drive and created a brand new, vanilla installation of Unraid using the USB Creator tool.

• No Config File: The boot fails even without my old config folder present.

• Replaced OS Files: I have tried manually replacing the bz* files with fresh ones from the Unraid zip.
  

2. Hardware Testing & Isolation:

• RAM: I ran Memtest86+ overnight for 10 full passes with zero errors. The RAM is known good.

• Hardware Changes: The only recent hardware change was a new LAN card. I have physically removed the card, but the boot issue persists.

• USB Drive Note: I have been using the same USB flash drive throughout this process.
  

3. BIOS Configuration (MSI Click BIOS 5):

• Started with Defaults: I began by loading "Optimized Defaults" for a clean slate.

• Set Unraid Defaults: I have meticulously configured the BIOS for Unraid, including:

  • Virtualization (VT-x/SVM) & IOMMU (VT-d/SR-IOV) Enabled.

  • Fast Boot & Secure Boot Disabled.

  • SATA Mode set to AHCI.

  • "Restore after AC Power Loss" set to Power On.
    

No matter what I try, the result is the same: a hard freeze during the initial boot sequence.

At this point, I am leaning towards a core hardware fault (Motherboard, PSU, or even CPU?), but I'm completely out of ideas for how to diagnose it further.

Has anyone seen anything like this before? I would be grateful for any suggestions on what to test next.

Thanks in advance for your help.

If it happens with a fresh install, it suggests a hardware issue, though it would be worth it to retest with a different flash drive.

I think so too. Just ordered a 32GB flash drive 2.0 as recommend on Unraid document from Amazon this morning, now waiting it to arrive and give it a go.

Sad news. After swapping in a new USB flash drive it still doesn't help.
I'm assuming there's a chance that it's motherboard related now, but if anyone have some other ideas in mind please do let me know.

Have you found a solution? Since Saturday, I've had a very similar problem and I have MSI Click BIOS 5 too, don't know if this could be related...

Edited September 22, 2025Sep 22 by yoda42

I read a post somewhere that the op has pretty much the same issue as I did. His/Her issue at the end of the day was because of a bad CPU.
So just to test things out, I tried replacing mines too. Swapped in a new CPU and everything just works again.
Finally got it fixed today.

TL;DR
If you're encountering boot up issues follow the following test sequences:

1. Run MemTest for a night to check RAM errors.
2. Swap in a new flash drive to test if the flash drive is dead
3. If all things above doesn't seem to be the issue, it's highly possible that the CPU is causing the issue.

Edited September 23, 2025Sep 23 by zorbajwhk

Well, you're right, it's my processor... I replaced it with an old one and everything works... My processor wasn't even a year old...