No. Even with Bronze Age relics, if something was made with an unknown tool, or unknown input, it becomes much, much harder to figure out how to make it. A good example is "how did they build the pyramids?" is still a matter of debate.
With a smartphone, to figure out how to make one, the Romans would have to:
- Invent an electron microscope to look at the CPU to figure out it's not just magic
- Discover quantum physics to invent an electron microscope
- Discover the electron and photon
- Discover chemistry and electricity so they can discover the electron
- Achieve a basic understanding of light so they can discover the photon
- Discover semiconductors
- Discover classical physics so they can discover quantum physics
- Invent calculus
- Invent statistics
- Invent algebra
- Invent the Cartesian plane
By the time they've done all that, centuries have passed, and so much has changed due to this technologies and discoveries that they're not "the ancient Romans" any more. Even if we gave the Romans something that didn't require a microscope, like a Model T, they still wouldn't figure out how to make one because they'd have to invent the blast furnace and the moving assembly line, none of which discoverable from the materials and parts.