What symptoms will a used iphone show if its internal components were replaced?

What symptoms will a used iphone show if its internal components were replaced?

I don't think someone would go through the trouble to replace all the components inside of an iphone.
If they did, it was the factory that did it anyway, you would not be able to get into it and put it back together without noticeable gaps / modifications.

To be honest I don't believe anyone would go through the trouble, however… There are counterfiet items on the market, everywhere, especially ebay. So you may have a counterfeit product, I don't think anyone has made counterfeit iphones but you never know, If your worried get a refund.

Here's a quick youtube, yea they make em.

I NEVER buy headphones online EVER, even off amazon. When I buy headphones I buy directly from the maker such as monster. I go to monster's website and buy it, I don't trust anything when it comes to headphones anymore.