I attached a couple pics of a cell phone I have a question about. its a Samsung galaxy s4 what are the things located in red circles? they look like a test point or connector for external antenna. but the small ones are covered by the rear frame and couldn't possibly connect to anything.

 

I attached a couple pics of a cell phone I have a question about. its a Samsung galaxy s4 what are the things located in red circles? they look like a test point or connector for external antenna. but the small ones are covered by the rear frame and couldn't possibly connect to anything.

It seems like high frequency transistor for GHz.

 

Shielded RF test points.

 

Shielded RF test points.

That's why I can't find the similar parts.

Do you think the testing method is the same like this.

 

Sorry i don't open DOC files.

And I'm not an expert on RF test connectors anyway.

 

but the small ones are covered by the rear frame and couldn't possibly connect to anything.

Sure they could. I'd imagine the larger ones are for quick testing of a particular characteristic by a repair department. The smaller ones, requiring removal of screws to access, are probably involved in either lower-level repair diagnostics, or pre-shipment quality control testing.