Billy Ray Cyrus was hit with brutal tech issues during his performance at the Liberty Ball to celebrate Trump’s inauguration -- and yeah, it was a total cringe-fest.

It all went down Monday night, and Billy was already on the struggle bus -- rocking a hoarse voice, no band, and attempting an a cappella version of Lil Nas X's "Old Town Road" ... yeah, the one he featured on.

It was already heading toward an epic fail, and Billy seemed to know it -- trying to hype up the crowd to sing along. But then ... dun, dun, dun -- his guitar cut out.

Billy, clearly desperate, pled with the backstage crew, "Is anybody awake? Where's everybody at? Is anyone back there? Can somebody turn my guitar back on?" -- but no luck.

BRC tried to spin it, though, pointing out Carrie Underwood had tech issues earlier too. Using it as a life lesson, he told the crowd ... "In life, when you have technical difficulties, you just gotta keep going. Or as President Trump would say, 'You gotta fight!'"

He then went for an a cappella take on his 1992 hit, "Achy Breaky Heart" -- but let’s be real, the whole thing was a hot mess, and fans online wasted no time roasting it, calling it downright embarrassing.