If you haven't found it yet, check the mall in Miral. Upper floor, in the larger section is an electronics store (next to the janitor's closet). The stuff will spawn there occasionally. I think some of the zombies in formal clothes near the banks will spawn them as well - but the mall is the most regular place.

You can also find it dropped by zombies on top floor of every skyscrapers in Mirai. They can drop PDA, calculator and electric components.