The Return of Optimus Prime

Here's what i don't get, is why in the movie Optimus prime die's and all that happens is he lose's colour, but when Ultra Magnus dies he explodes into massive chunks of his former self.
But then they just get the Junkions to, glue and polish him back together, surely they could of done the same for prime.
Or they could of kidnapped a Quint to revive him, because thats what they did in the episode "The return of Optimus prime".
Surely they didn't care about him enough to try everything, all they did do was strap him up to some type of colour monitor and let Perceptor look at him in his Telescope mode.
But then they just get the Junkions to, glue and polish him back together, surely they could of done the same for prime.
Or they could of kidnapped a Quint to revive him, because thats what they did in the episode "The return of Optimus prime".
Surely they didn't care about him enough to try everything, all they did do was strap him up to some type of colour monitor and let Perceptor look at him in his Telescope mode.
