Mariah Carey Says BS to Dick Clark Prod Sound Check Claim (PHOTOS + VIDEO)

Mariah Carey's people are incredulous Dick Clark Productions is blaming her New Year's Eve trainwreck performance on her because she was too lazy to do a sound check ... Mariah did one, and the signs of trouble were already there.

The pics and video make it clear ... she did take the mic and do a check-in just after 3 PM. Our Mariah sources say the sound from her earpiece was "choppy" but the DCP production people assured her it would be fixed. She continued having problems, but claims she got false promises the sound would be fixed when she took the stage for real.

TMZ broke the story ... Mariah's team has accused DCP of sabotaging her performance with a bum earpiece to win bigger ratings ... something DCP claims is defamatory.

As for DCP's claim she had her stand-in do the sound check, we're told the stand-in did the dance routine but Mariah herself did all the vocal stuff.

Based on the pics and the video, score one for Mariah.