Can the movie possibly be "Gunhed""Gunhed" (1989)?
In the early 2030s, a new material called Texmexium (more powerful than nuclear energy) enabled the world to be controlled by a new generation of super computers. Due to fear of misusing Texmexium, it was guarded within hyper-nuclear facilities that powered every major city. Concurrently occurring was the world's depletion in raw materials to create new all-powerful computers; conductive plastics and computer chips have out-valued gold and gave rise to tech scavengers that seek their fortunes through acquiring and selling computer parts despite the extreme dangers.
The scene in Gunhedyou're describing happens toward the end and involves the protagonist holding the robot's arm and firing projectiles that result in an explosion and we see him lying on the ground for a moment, status unknown. Happens in the last 10 mins. or so.
It's revealed shortly after that he is still alive though.
still alive!
