Odd Cold Boot Issues - Mobo or CPU£

Hey all, I should've posted here first but here I am now. I originally emailed AsRock multiple times for this issue, and have yet to get any response. Below is my predicament; updated and streamlined from my original emails and support requests:

From day one, I've been having odd USB dropout issues, with the timeline below:

- Mouse and keyboard both stop intermittently responding, soon followed by the USB disconnect and reconnect sounds
- Audio starts to crackle and jump
- System eventually hangs as I cannot control any input, sometimes ends with BSOD, forcing me to restart via the reset button on the case

Specs are as follows:
Asrock B650M PG Riptide mATX
Seasonic Focus GX Gold 80+ 750W
Ryzen 7 7700 AM5 @ 38GHz
G.Skill Trident Z 32GB DDR5 6000 (Samsung chips) - Used at both stock 4800 and 6000/5800/5600/5400 XMP
Asrock RX 7800XT 16GB
500GB Inland Pro NVMe (OS) - 2TB Samsung NVMe - 1TB Crucial MX500 SATA - 1TB WD Blue HDD - 4TB WD Blue HDD
Windows 11 Pro
Thermaltake Core v21 Case

The oddest of all of this, is that it only happens on first cold boot, whereas upon restart, the system behaves completely normal, so much so that I've been able to play many games without any interruption or performance issue. If I leave the system off for ~30min+, the issue returns on next boot, but again, is remedied by a follow up reboot.

I've also been adamant to check the Event Viewer to see of any anomalies. Nothing jumps out and mentions any particular crashes.

I've tried almost all steps I could think of to remedy this:

- Pulled all unnecessary hardware then added back piece by piece (one stick of RAM, no video card, no SATA drives, no excess USB connections)
- Updated and downgraded BIOS - tried 1.21, 1.24, 1.28, 1.29AS01 beta, 1.30AS05 beta, 2.00? (Just noticed 2.02 has better USB compatibility...)
- Tried turning on/off Deep Sleep in S4 & S5
- Turn off USB Selective Suspend
- Turn off USB power management in Device Manager
- Turn off PBO in BIOS - limit to 3.8GHz
- Change RAM timings from default JEDEC to XMP
- Change RAM from XMP 6000 to 5800/5600/5400 and default JEDEC @ 4800
- After first reboot, stress tested CPU/RAM via Prime95 blended torture test
- Tested latency with LatencyMon - seized up after ~7 minutes on cold boot, just app and peripherals, until crash
- Purged and reinstalled AMD B650 chipset drivers
- Replaced G.Skill RAM with new, separate set of Corsair Vengeance 32GB DDR5 (on QVL) - issue persists
- Replaced PSU with original unit (650W Seasonic Gold), no video card for lesser power draw - issue persists
- Used Verifier tool in Windows to force crash upon 3rd party driver testing. Different driver issue every time. First was SteamStreamingSpeakers.sys; then AsRock's appdrv01.sys, etc.
- Tested options outside of main OS
- Linux Live CDs - Mint and Ubuntu both work flawlessly.
- Hiren's Boot PE (legal version) - works flawlessly
- Windows 11 Pro safe mode - works flawlessly
- Fresh install of Windows 10 Pro - Used a spare SSD without any other drives attached. Same issues as Win 11 Pro. This part makes me think it's not a driver issue.

I tested the above first bullet point with a Prime95 Blended Stress Test in between each added component, with a full shutdown and removal of power (turn off PSU and purge residual) between testings. Minimum of 30 minutes in between tests (so this took some time!)

Sorry for the long first post, but right now I'm stuck between thinking this is a thermal issue (warming up and then working), a CPU issue that I'm not familiar with, or the board is being a pain.

As noted above, I see that a new BIOS just dropped yesterday with better USB compatibility, so that could be promising.

If anyone has any inkling, guidance, thoughts, prayers, etc, please contact me. I'm currently on my older AM4 build with the PG 7800XT and all is working fine. Thanks!

Hah thanks, the detail was from quite a bit of prior emailing and support ticket stuff as testing went on. I initially emailed ASRock at support@asrockamerica.com, followed up through the email a 2nd time, and then contacted them through the support form, which you linked.

As for testing the RAM, yeah, I had swapped out the G.Skill 2x16 kit for a Corsair Vengeance 2x16 kit, and both were on the QVL. Never ran overnight testing, but the RAM would fail at higher OCs, including the marketed 6000MT/s both packs are labeled as. I never tested the Corsair though, as by that point the issue had been going on that I just called it there that it wasn't RAM. I suppose it is chance to could've gotten another bad set, but it seems too high a probability of that.

So yeah, overall I suspect it's the board, but I suppose it could be the CPU. I'm leaning board only b/c Prime95 seems pretty stable even on long tests (7-8 tests; 1-2 hours), unless I have the RAM clocked to 6000.

Since I'm back on my old setup (minus the 7800XT), I'm probably going to look into RMAing both board and CPU since those are the only two culprits left.

Thanks again for the response :)

Good luck, let us know how it turns out

Well, that was to good to be true. I installed the mobo and all back in the case and hooked everything back up. within 10 minutes of boot, the stutter came back. The only thing I readily noticed was different than my external testing was that I hooked up the 4pin 12v connector in the case, versus not having the respective cable available when I had it outside the case (2 different PSUs, both exhibited the issue I'm here for). So I'm thinking, let's disconnect the 4pin and see if anything changes. Outside of that, maybe a short within the case? I have other cases I can use, so I suppose it's a possibility.

Otherwise, I'm back to square one, and going to look into RMA if things don't improve.

EDIT: That didn't work. I gutted the entire system and I'm using it like was last night. Testing continues.

EDIT 2: So it happened even outside the case this time. I'm suspecting either the surge protector or ethernet cable. I swapped both out, and I'm piecemealing the system back together outside the case.

Thanks Xaltar. I've put together my old rig for the time being, with the good additions being the 2TB m.2 and 7800XT. I've also submitted an RMA request to AMD, as I'm completely stumped on if this is board or proc. Hopefully I find it out through the processes of both ASRock and AMD.

Regarding such, are you aware the turn-around time on these technical requests at ASRock? Any chance of an average wait time on response? I understand if you don't know or aren't privy to that information.

Thanks again for the support.