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ZDNET's key takeaways

• DisplayPort cables are designed to transfer power to monitors.
• With cheaper options, misaligned pins may cause power failures.
• You can avoid this by opting for a VESA-certified DisplayPort cable.

The DisplayPort "Death Pin" -- officially recognized as the Pin 20 Problem -- is a notorious manufacturing oversight where the final pin on a cable is wired to carry a live current it was never meant to handle.

By creating an unwanted electrical bridge between your monitor and graphics card, this defect allows power to flow in both directions, often leading to fried circuits and total system failure. In an era where a high-end GPU can easily set you back $1,500, double-checking your cables is a necessary bit of insurance to keep your Nvidia or AMD hardware from turning into a very high-tech paperweight.

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Fortunately, the best solution is as easy as selecting the right DisplayPort cable. But there are a few things you need to understand first in order to see how the Death Pin can wreak havoc on your PC or workstation. 

What is Pin 20?

If you've ever looked at the end of a DisplayPort connection, you may have noticed a series of small, gold-colored connections lining the inside. Each is nestled in a tiny notch made to fit the corresponding contact in your monitor's DisplayPort input, and you'll be able to count 20 pins (as opposed to HDMI's 19-pin configuration). 

Each pin is designed for a specific function, mostly electrical grounding and audio/video transfer. But as I explained before, the 20th pin is designed to carry an electrical charge between connection points. 

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This is because a DisplayPort connection was designed to allow you to set up things like docking stations or adapters without needing a dedicated power adapter. However, as of 2013, VESA mandated that all DisplayPort cables must leave Pin 20 disconnected in "passive" DisplayPort-to-DisplayPort cables due to increasing reports of malfunctioning cords and devices caused by electrical feedback. 

Why it's called the 'Death Pin'

When a cable is made incorrectly and connects Pin 20 end-to-end, this creates a full electrical circuit between your GPU and display. That means that power is flowing between them, which can cause a host of problems, including:

• Short circuits: Both your display and graphics card will try to feed power through the DisplayPort cable. And since they will have different voltage requirements, this can rapidly overheat your cable, causing an electrical short or even a fire.
• Backdriving power: Your PC tower or laptop can be fully powered down, but if your monitor is in standby or sleep mode while plugged into a wall outlet, it can trickle-feed power back into your computer. This can cause all kinds of electrical problems that range from eternally-spinning GPU fans to your PC not being able to boot up at all.
• Component failure: If a short or power backdrive is powerful enough or goes on for long enough, it will physically damage delicate components like RAM sticks, graphics cards, and motherboards. Electricity likes to take the path of least resistance, and can even leave physical evidence on circuitry (melting, warping, etc.), bricking your system. Hence, the nickname.

Symptoms of a bad cable

If you suspect you've got a bad DisplayPort cable, there are a few things to look out for:

• Your PC won't wake from sleep mode or gets stuck in a boot loop
• GPU fans and motherboard LEDs remain on after shutdown
• Graphical artifacts and screen flickering

How to avoid it

Thankfully, it's pretty easy to prevent a catastrophe by keeping an eye out for official VESA certification logos, which indicate which brands have submitted products for VESA DisplayPort testing to ensure that designs do not connect Pin 20. Established, well-known brands like Lenovo, Dell, and Anker all regularly submit DisplayPort cables for verification. 

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And while they may be a bit pricier, it's worth paying extra for peace of mind. Lesser-known brands often cut production costs by skipping VESA testing, making it easier for defective cables to reach store shelves and shipping warehouses. 

If you've got experience with electrical repairs, you can use a multimeter to check whether your cable has a full Pin 20 connection. If you get a reading or experience any symptoms of a poorly made cable, disconnect and toss it immediately, and replace it as soon as possible. 

ZDNET's bottom line

While most newer graphics cards are designed with protective circuitry to prevent power backdrive damage, using an uncertified cable still runs a significant risk. Without VESA certification, it's nearly impossible to know whether Pin 20 is connected before you connect it. And electrical problems can cause severe, cascading damage almost instantly. 

But choosing VESA-certified DisplayPort cables from reputable brands means a protection guarantee and keeps your workstation or gaming PC from becoming landfill fodder.