Oakland Raiders owner Al Davis died from a broken heart ... this according to his death certificate obtained by TMZ.

The document reveals three primary causes of death:

A) Ventricular fibrillation -- a dangerously abnormal heart rhythm
B) Congestive heart failure
C) Cardiomyopathy -- heart muscle disease

According to the death certificate, Al died at the Oakland Airport Hilton at 2:45 AM on October 8th.

The document shows Al had been diagnosed with cardiomyopathy years ago ... and suffered a ventricular fibrillation just 15 minutes before his death. Davis also suffered from Merkel cell carcinoma -- an aggressive form of skin cancer.

According to the doc, Davis -- who was involved with the NFL for 60 years -- underwent throat surgery just three days before his death. Davis also had heart surgery in 1996.

Al was 82 when he died.

Legendary NFL running back Eric Dickerson played for the Oakland Raiders for one year back in the '90s ... but it's clear, he had NO LOVE for Al Davis.

Dickerson was out in L.A. last night -- when he made a huge statement about his former boss, without having to say too much.

But when we asked about his other former team -- the struggling Rams -- Dickerson couldn't have been more blunt ... it's time to come back to Los Angeles!!

Al Davis, the legendary owner of the Oakland Raiders, died today at the age of 82.

The team announced his death on their website, with no further details. They did released a statement saying, "Al Davis was unique, a maverick, a giant among giants, a true legend among legends, the brightest star among stars, a hero, a mentor, a friend."

NFL commissioner Roger Goodell said Davis "defined the Raiders and contributed to pro football at every level. The respect he commanded was evident in the way that people listened carefully every time he spoke. He is a true legend of the game whose impact and legacy will forever be part of the NFL."

Davis has been involved with the NFL for 60 years, starting off as an assistant coach with the San Diego Chargers. He was inducted into the NFL Hall of Fame in 1992.

Davis was famous for coining the phrases "commitment to excellence" and "Just win, baby."

The Raiders won Super Bowls XI, XV and XVIII ... but have struggled mightily the last several years.

Just a month ago, we asked broadcaster Al Michaels if the Raiders would ever win with Al Davis running things. His answer was very clear.

Snoop Dogg, a famously huge football fan, tweeted his thoughts today on the passing of Al Davis.

Davis passed away Saturday morning at the age of 82.

NFL Hall of Famer Michael Irvin knows what it takes to win a Super Bowl ... or three ... and last night, he spoke out AGAINST Al Michaels ... saying the Oakland Raiders CAN win a championship during Al Davis' lifetime.

Irvin told TMZ ... it doesn't matter who's running the front office -- insisting the PLAYERS ultimately determine the success of an NFL franchise.

It's great logic in theory ... but Davis is the man who puts the players on the field -- and over the years, he's picked guys like JaMarcus Russell and Andrew Walter.

So, we gotta ask ...

Oakland Raiders owner Al Davis believes Al Michaels secretly blames him for planting a FALSE news report about Michaels cheating on his wife a while back ... and suggests that's the REAL reason Michaels blasted him on TMZ over the weekend.

After the NFL announcer RIPPED Davis ... calling him a terrible owner who's probably gonna die soon ... Oakland Raiders P.R. Director Mike Taylor gave the following statement to TMZ:

"We have no idea what Michaels was blathering about.  I do remember Michaels being associated with an ultimately bogus report about adultery and other misdeeds and he thought Al Davis had something to do with it.  Al Davis had nothing to do with it."

"During the recent Raiders/Saints broadcast, Chris Collinsworth put Michaels in his place when Michaels was speaking about the Raiders.  John Madden did the same thing when he was in the booth with Michaels."

"We do not know what started this."

FYI -- The "report" Taylor is referring to was a radio station prank back in 1997 ... and as Taylor pointed out, there was NO TRUTH to the notion that Michaels ever committed adultery. 

The Oakland Raiders will never EVER win another Super Bowl as long as the owner Al Davis is alive and breathing ... so says legendary "Sunday Night Football" announcer Al Michaels.

Al was leaving Boa Restaurant in Hollywood last night, when our photog -- a HUGE Raiders fan -- asked point blank, "Are we ever going to win a Super Bowl while Al Davis is still alive."

Michaels' response -- "NO."

FYI -- Davis is an NFL Hall of Famer who is largely credited with merging the AFL with the NFL ... and transforming the league into the POWERHOUSE it is today. But in the past decade, he's come under some serious fire ... because the Raiders are terrible.

Still, when we asked Michaels if he considered Davis a genius, he told us, "If you had a team that lost 11 or more games in SEVEN consecutive years, would you say a genius ran the team?"

No, we would not.

NFL bust JaMarcus Russell is still paying for the mess he made in Oakland ... but this time it's a good thing.

TMZ has learned ... the #1 overall pick in the 2007 Draft was hit with a $223,180.05 lien by the State of California Tax Board for failing to pay his taxes in 2008 ... when he still played for the Raiders.

But this story has a happy ending, because according to court documents filed in Alameda County, CA -- JaMarcus recently paid off his debt the lien has been released.

Russell still has ties to Oakland -- where a $2.4 million mansion he owns is still in foreclosure and is set to be auctioned off next month ... unless he decides to pay off the debts and penalties.

FYI -- Russell famously signed a RIDICULOUS contract worth around $60 mil in 2007 -- and then proceeded to only win seven games in three pathetic seasons.

NFL legend Ray Guy -- widely considered the GREATEST punter of ALL-TIME -- has been forced to sell off his three SUPER BOWL rings after filing for bankruptcy back in the spring.

61-year-old Guy -- a seven-time Pro Bowler -- banked a total of $80,100 for the three rings he earned during his 14-year NFL career ... two while the Raiders were in Oakland ... and one after the team moved to Los Angeles.


The rings (pictured above) were purchased by an unidentified buyer through an L.A. auction house.

After the sale, a clearly saddened Ray told the Augusta Chronicle, "I don't want to talk about it. I'm not trying to be hateful, but sometimes you've got to do what you've got to do."