Zephyrus G14 GA403WR dGPU completely dead (Code 43 + HDMI dead) — deep diagnostics inside, looking for anyone with similar failure Post:

Hey everyone,

I’m dealing with a pretty serious issue on my ASUS ROG Zephyrus G14 GA403WR where the dedicated GPU suddenly stopped working. I’ve spent the last couple days doing deep diagnostics across Windows and Linux to rule out software issues, and I’m trying to figure out whether anyone else has seen this exact failure pattern.

Symptoms:

• Windows shows Code 43 (CM_PROB_FAILED_POST_START) for the NVIDIA GPU
• HDMI port is completely dead
• iGPU works normally
• GPU is detected in Device Manager but never initializes
• Artifacts appear when the driver attempts to initialize the GPU
• Safe mode works normally
• Multiple clean driver installs (DDU etc.) didn’t help

I booted into Ubuntu live to eliminate Windows issues.

Linux diagnostics:

lspci -nn | grep -i nvidia
64:00.0 VGA controller: NVIDIA Corporation Device [10de:2f58]
64:00.1 Audio device: NVIDIA Corporation Device [10de:2f80]

GPU enumerates correctly on PCIe.

Config space is readable (not all FF), which means the PCIe interface is alive.

Power state:

D0
active

PCIe link:

Gen4 x8

AER registers show no PCIe errors.

But this is the suspicious part:

Attempting to read the VBIOS ROM returns 0 bytes:

VBIOS ROM read result: 0 bytes

Which suggests the GPU cannot serve its own firmware.

Other observations:

• HDMI output completely dead
• Windows Code 43 persists across driver versions
• Linux drivers also fail to initialize the GPU
• GPU power sequence completes correctly
• ACPI tables and power methods appear intact

So at this point the likely causes look like:

1. VBIOS corruption or SPI ROM failure
2. VRAM training failure
3. GPU display engine failure
4. Rare board-level issue

ASUS support says I need to ship the laptop back to the US because it was purchased from Best Buy, which is painful since I’m currently in India.

Has anyone seen this specific pattern on a G14 (especially GA403 series)?

Particularly interested if anyone has had:

• VBIOS corruption
• board-level repair success
• HDMI + Code 43 combo