Microsoft has followed through on its promise to release a docu-series celebrating its 20th anniversary. The six-part series has been posted to Xbox's YouTube channel and goes over everything from the birth of the brand to the recent purchase of Bethesda.

And while most episodes span years of Xbox's history, there's one chapter that's entirely devoted to a single crisis: the dreaded Red Ring of Death.

For those who weren't around for the Xbox 360 days, the Red Ring of Death was what every Xbox 360 owner feared. A series of three red lights and a blinking green light meant that there was an internal hardware problem with the console, and that problem most often meant it had gone to the big Xbox farm in the sky.

For years, Xbox fans thought the cause of the Red ring of Death was a problem with the Xbox 360's cooling system, and they were at least partially right. As revealed in "Power On: The Story of Xbox - Chapter 5: The Red Ring of Death," it wasn't that Xbox 360s were overheating but actually an issue called thermal expansion.

Related: The "Step Out Into The World" Moment In Fallout 3 Is One Of My Favourites In Gaming

Todd Holmdahl, head of Xbox hardware until 2014, said in the documentary that most of his time at Xbox from 2006 to 2007 was spent trying to figure out the root cause of the Red Ring of Death. For months, the best of the best at Xbox scoured every component, resistor, wire in the 360 to see what was causing the issue.

"The breakthrough came when we understood that the connections that were being broken were not located on the motherboard, but they were actually located inside the components," said hardware engineer Leo Del Castillo. "The reason it was breaking was thermal, but it wasn't because of peak temperature. It was because when the unit would get hot and then cold, hot and then cold, every time it did that it would stress the connection [between GPU and motherboard]."

Red Ring - via Know Your Meme
via Know Your Meme

Specifically, the soldering balls used to adhere the GPU to the motherboard were flexing ever so slightly every time the Xbox 360 was turned on. Over time, this flexing led to cracks that eventually prevented the console from working at all. This meant each and every Xbox 360 sold was a ticking time bomb waiting to go off.

Microsoft knew that this issue could kill Xbox as a brand. They had to do something big, and that big move was to fix and/or replace literally every Xbox 360 sold with no questions asked. The move cost Microsoft over $1 billion dollars in honored warranties, but it worked. The Xbox 360 nearly out-sold the PS3 and paved the way to the more technically successful Xbox One.

The issue with thermal expansion was eventually solved on the Xbox 360 "slim" model, but by sticking by the 360 through thick and thin, Microsoft cemented its stake in the home console market.

The Red Ring of Death isn't just a major turning point in Xbox history worthy of an entire documentary. It's also been honored in an official poster that you can buy for $25. Although, if you're one of the unlucky ones who endured one or more 360 deaths, maybe save yourself the PTSD and skip this one.

Next: Playing Skyrim As A Pure Mage Who Shuns Weapons Is The Most I've Enjoyed The Game In Ages