BIOS Update Causing Shutdown Failure – Dell G16 7630

@DELL-Nat M​

Issue Analysis – Shutdown Problem Linked to USB 3.1 Controller / PCIe Root Port

After extensive testing, I’ve identified that the shutdown/restart issue is not solved by simply downgrading the BIOS to 1.22 — the problem still occurs.

• When the USB 3.1 controller is enabled in Device Manager, the system does not shut down properly and instead restarts.

• When I disable the USB 3.1 controller, the system is able to shut down normally.

• Similarly, when I disable Intel(R) PCI Express Root Port #21 - 7A44, the system also shuts down normally.

This clearly shows that the bug is linked to the USB 3.1 controller / PCIe Root Port power management in the BIOS (v1.26.1 and even 1.22).
The affected devices are not being powered down correctly during the shutdown sequence, which causes the system to trigger a restart.

Temporary workarounds:

• Disable the USB 3.1 controller in Device Manager.

• Or disable Intel(R) PCI Express Root Port #21 - 7A44.

Impact:

• Disabling these devices makes USB 3.1 ports (and potentially other devices on that root port) unusable.

• Downgrading to BIOS 1.22 does not solve the issue.

Conclusion:
This is not a hardware defect from the user’s side, but a clear BIOS-level bug affecting power management of the USB 3.1 controller and PCIe Root Port.
Dell needs to release a corrected BIOS version to properly fix this behavior.

Dell G16 7630 – Shutdown Bug Diagnosed and Solved by Removing SupportAssist

Hi everyone,

I’d like to share my full troubleshooting journey with the Dell G16 7630, which was affected by a persistent shutdown bug. The system would restart instead of powering off, even when idle, cool, and connected to the original charger.

Initial Symptoms

• Shutdown triggered a fan surge and unexpected reboot

• BIOS logs showed Thermal No POST Recovery – Method 1 Executed

• Dell diagnostics returned error 2000:8135 (charger not detected) despite proper connection

• Disabling USB 3.1 controller and PCIe Root Port #21 did not solve the issue

• Downgrading BIOS to v1.22 had no effect

Troubleshooting Steps

1. Verified thermal and power status using PowerShell and BIOS logs

2. Disabled USB 3.1 controller and PCIe Root Port #21 in Device Manager

3. Tested shutdown via script: shutdown /s /f /t 0

4. Restored BIOS to factory defaults using “BIOS Defaults” option

5. Confirmed Modern Standby (S0ix) was active

6. Uninstalled Dell SupportAssist using PowerShell and manual cleanup

Resolution

After uninstalling Dell SupportAssist, the system began shutting down cleanly. No fan surge, no reboot, no BIOS recovery logs. This confirms that SupportAssist was interfering with the shutdown sequence, likely through background services or scheduled tasks.

Cleanup Steps

• Removed SupportAssist via PowerShell:

  powershell

  Get-WmiObject -Query "SELECT * FROM Win32_Product WHERE Name LIKE '%SupportAssist%'" | ForEach-Object { $_.Uninstall() }
  

• Deleted residual folders and registry keys

• Verified USB and PCIe devices were re-enabled and functioning:

  powershell

  Get-PnpDevice | Where-Object { $_.Status -eq "OK" -and $_.Class -eq "USB" }
  

Final System State

• BIOS v1.26.1 (July 15, 2025)

• SupportAssist fully removed

• USB 3.1 and PCIe Root Port #21 re-enabled

• Clean shutdown confirmed

• No thermal or charger errors

• Windows 11 Pro 23H2

• SK Hynix BC901 SSD (firmware 5109T51)

Recommendation

If you're facing similar shutdown/restart issues on the G16 7630, try removing SupportAssist completely. Dell should investigate how SupportAssist interacts with BIOS-level power logic and Modern Standby.

Hope this helps others. Feel free to ask if you want scripts or logs.

Best regards