D4vd's Lawyers Withdraw, Now Repped by Public Defender

9:12 AM PT -- Los Angeles D.A. Nathan Hochman is expected to address the media soon.

D4vd pleaded not guilty and is expected back in court on October 19.

D4vd has just suffered a big blow in his murder case ... his lawyers told the judge they can't rep him anymore, a public defender has stepped in, and it's apparent the singer has run out of cash.

Blair Berk, Marilyn Bednarski and Regina Peter told the judge they are unable to continue representing D4vd. Although they did not give a reason, everything screams ... D4vd is broke.

Berk, Bednarski and Peter tell TMZ ... "This morning the court granted our request to withdraw as counsel and appointed the Los Angeles County Public Defender's Office, after it was determined David qualified for appointed counsel."

The lawyers go on ... "We continue to support David and his defense against these serious charges. We are grateful that the Los Angeles County Public Defender's Office has taken over the representation and that David has a highly capable and committed team of attorneys and investigators behind him."

A public defender has stepped in, citing the fact D4vd is indigent.

It's a stunning twist, given that D4vd made at least $11 million from his Interscope record deal.

It doesn't seem D4vd has blown a ton of money -- the 21-year-old was living in a rental house, and there were no flashes of outrageous spending. It's unclear how his fortune was depleted.