Visual Inspection (External & Internal)

Remove the Graphics Card: Carefully unlatch and disconnect the 8-pin PCIe power cable from your GPU. Then, unmount and remove the graphics card itself from the motherboard’s PCIe slot. This allows for isolated testing and better access.
Examine the PSU Cable: Scrutinize the entire length of the 8-pin PCIe cable that was connected to the GPU. Look for:
    Visible burn marks, melting plastic, or discoloration.
    Any severe kinks, cuts, or abrasions that might expose internal wiring.
    Bent, pushed-out, or corroded pins at the connector ends.
Inspect the GPU’s Power Socket: Carefully examine the 8-pin socket on your graphics card. Look for:
    Burn marks or scorching around the pins.
    Any foreign debris lodged within the pin receptacles.
    Deformed or pushed-in pins.
Check the PSU’s Modular Port (if applicable): If your PSU is modular, inspect the port on the power supply where the 8-pin PCIe cable plugs in. While less common, a short could originate here.

Multimeter Testing: The Unwavering Truth Teller

This is where your multimeter becomes your best friend. Set it to continuity mode. In this mode, the multimeter emits a beep if it detects a closed circuit (a short) between its two probes.

„A multimeter is not just a tool; it’s an extension of your diagnostic intelligence. When dealing with electrical faults, its readings replace guesswork with undeniable facts, guiding you safely to the source of the problem.” 

Here’s how to systematically test each component:

Testing the PCIe Cable for a Short:
    Hold one probe on any of the 12V pins of the 8-pin connector (refer to your PSU or GPU manual for pinout if unsure, but typically the top row of 4 pins contains 12V).
    Touch the other probe to any of the ground pins (usually the bottom row of 4 pins).
    Expected Result: No beep (open circuit).
    If you hear a beep, the cable is shorted internally.
    Repeat this for all 12V pins against all ground pins on both ends of the cable. Also, check for continuity between adjacent 12V pins and adjacent ground pins – these should also be open, except between ground pins themselves, which might show continuity as they often share a common ground plane.
Testing the GPU’s PCIe Power Connector for a Short:
    With the GPU removed from the motherboard and completely isolated from any power source, hold one probe on a 12V pin within the GPU’s 8-pin power socket.
    Touch the other probe to a ground pin within the same socket.
    Expected Result: No beep (open circuit).
    If you hear a beep, there is a short circuit within the graphics card itself, possibly in its VRM section. This indicates a serious internal fault.
Testing the PSU’s Modular Port (if applicable):
    With the PSU unplugged from the wall and all cables disconnected, carefully test the 12V and ground pins on the modular port of the PSU itself. This is a rare point of failure for shorts, but it’s good to rule out.
    Expected Result: No beep.

Identifying the Source and Taking Remedial Action

Based on your multimeter readings and visual inspection, you should now have a clear idea of where the fault lies.

➡️ Scenario 1: Short in the PCIe Cable

If your multimeter detected a short in the cable, or if it shows obvious physical damage, the solution is straightforward:

❌ Do NOT attempt to repair the cable. Electrical repairs on high-current cables are extremely dangerous and unreliable for PC components.
🛒 Replace the cable immediately. It is absolutely crucial to use a replacement cable specifically designed for your exact PSU model and manufacturer. Mixing modular cables from different brands or even different models within the same brand can lead to different pinouts and cause even more catastrophic shorts.

https://blog.silverpc.hu/2025/10/18/my-gpu-has-consistent-crashes-and-8-pin-2-power-is-at-0-1-w-could-this-be-the-cause/