Mark Ronson went from the DJ booth to a hospital bed … and it sounds like he was trying to do way too much.

The producer/DJ just posted a photo of himself in the hospital, explaining how some heavy lifting during a DJ set resulted in him needing medical attention.

Mark says he was in the middle of a mix when he tried to turn the stage monitor towards the crowd to “give them some extra juice.” Problem is, Mark says the stage monitor weighed way more than he thought and he ended up popping two tendons in his bicep.

Mark is hoping some laughter eases the pain, ending his post with some light-hearted humor, writing … “Here we are, baby! #tornthisway”

Despite the painful muscle injury, Mark says he finished his set before seeking medical attention.

Val Kilmer had been dogged by rumors that he was a Hollywood diva and a pain to work with … but one costar and friend tells TMZ that’s a total crock.

Danny Trejo, who was among the star-studded cast of “Heat” with Val, tells TMZ … Val got a bad rap for being difficult to work with — but the icon wasn’t high-maintenance — he was a “perfectionist.” There’s a big difference, DT makes clear.

As you sadly know … the legendary actor died Tuesday at the age of 65 — his death sending shockwaves through Hollywood as most didn’t realize his health had deteriorated so severely.

Highlighting what a thoughtful dude Val actually was, Danny shared one of his favorite memories from their time on “Heat” — and it’s kinda a tear-jerker now.

One day, Val showed up to set wearing a fancy and obviously very expensive leather jacket — and Danny commented on how much he liked it. The next day, there was one in his trailer … a gift from Val.

Danny says the only issue he ever had with Val … his pal didn’t get nominated for an Oscar as Doc Holliday in “Tombstone.”

Christina Fulton is another one of Val Kilmer’s heartbroken former costars … speaking to us about her favorite memories with him.

TMZ caught up with Christina outside the courthouse in Downtown L.A. Tuesday during her legal battle with her son — and she essentially spoke to the late actor through our camera, thanking him for being kind and generous to her on set for their ’91 movie “The Doors” when she was a new actress in L.A.

Catch the clip — Christina shares more personal words about the lasting impact Val had on her, and it’s truly heartbreaking … especially since they kept in contact over the years.