[BUG] RTX 5090 — nvlddmkm.sys WATCHDOG 0x1b8 on Sleep/Hibernate Resume and Restart — 215 dumps since Aug 2025

Summary

After resuming from S3 sleep, S4 hibernate, or after a system restart, the system produces a black screen with no display signal. The machine remains powered on but unresponsive, requiring a hard reset. During normal use (gaming, rendering, desktop) the system is completely stable.

Windows LiveKernel generates a WATCHDOG4401 dump on every occurrence. Analysis of 215 dumps shows a 100% consistent crash signature across all driver versions.

Dump analysis (all 215 dumps identical)

BugCheck:  0x1b8 (WATCHDOG_TIMEOUT)
P1:        0xa  — GPU hardware scheduler timeout (MCDM/kernel-mode)
Module:    nvlddmkm.sys  (present in 100% of dumps)
           dxgkrnl.sys   (present in 100% of dumps)
Context:   exclusively on power state transition (S3/S4 resume, restart)
Normal use: zero occurrences

Reproduction steps (not always)

1. Allow the system to enter S3 sleep or S4 hibernate, OR initiate a system restart.

2. Resume / wait for the reboot cycle to complete.

3. Display goes black with no signal. System remains powered on, unresponsive.

4. Hard reset required. WATCHDOG4401 dump generated in C:\Windows\LiveKernelReports\WATCHDOG4401\

Expected: Normal resume / boot with display signal restored.
Actual: Black screen, no signal, hard reset required.

What has been ruled out

-– Hardware defect: system is fully stable during all non-transition usage including heavy gaming and rendering.

-– Driver installation corruption: DDU clean install confirmed, multiple times.

-– Specific driver version: every driver release from Aug 2025 to Apr 2026 affected. Same crash signature.

-– Third-party software conflict: occurs regardless of running applications.

Partial workaround

powercfg /h off   (disable hibernate)
+ disable Fast Startup in Power Options

This reduces occurrence frequency but does not eliminate the issue on S3 resume or restart. A driver-level fix for the D3cold->D0 / power state transition path in nvlddmkm.sys on Blackwell (GB202) is required.

Related reports

Identical root cause documented in: [BUG] RTX 5090 Hibernate Resume causes nvlddmkm.sys 0x133 DPC_WATCHDOG — NVIDIA Developer Forums, March 28 2026 (thread #364994). That report covers the 0x133 variant of the same power-state transition failure on identical Blackwell hardware.