8:24 AM PT -- A source close to Cube wouldn't speak directly to the lawsuit, but tells us Cube has loaned Jinx money over the years that has not been paid back ... so clearly, the two have beef.
Ice Cube has some cash that's long owed to someone who made dozens of beats for him over the years ... so claims the guy, who's now taking the rapper to court over it.
Producer Sir Jinx just sued Cube for what he claims are unpaid royalties he recently discovered are due to him for production work he provided to IC. If you're not familiar, SJ helped make a bunch of Cube's beats dating as far back as his first album in 1990, "AmeriKKKa's Most Wanted."
According to the docs, obtained by TMZ, Jinx says he's produced upward of 28 tracks for Cube ... and that it wasn't until 2019 that he realized he wasn't getting his fair share of the profits.
So, to make things right, Jinx says he reached out to Cube's team to let them know there was some back pay that needed to come his way ... but in the end, Jinx claims Cube never forked over the dough.
Jinx claims he's incurred damages north of $100k ... and he's asking a judge to get a proper accounting in place, and to award him whatever he deserves according to his contracts.
Sir Jinx has a list of what songs he believes he got stiffed on -- and they include some of Cube's best-known songs, including ... "No Vaseline," "True to the Game," "The Bomb," "It's a Man's World," "The Funeral," "Who Got the Camera?" and several more.
As time went on and Cube continued to make albums into the 2000s and beyond, Jinx was featured less and less. It looks like he was mostly influential in Cube's early sound after leaving N.W.A.