Samsung has shown integrity on this issue, and I respect that. It is reported that about 200,000 devices were used for the investigation. The investigation, according to reports, covered all areas of the the phone's technology, both software and hardware. They also consulted three (3) other tech firms to carry out their own investigation so as to achieve the best results.
In summary, their findings are as follows:
1. The first set of Note 7s had a problem in the batteries. The positive and negative terminals are separated by a thin material called "separator". At the upper right corner of the batteries, a manufacturing error created a situation where breach of the separator would eventually happen, as the phone would be used (basically a ticking time bomb if you ask me ). The two terminals would then touch (short circuit) leading to serious heating and eventual explosion.
2. A second batch of phones was released into the market, which still had this issue and another one. This time, not only would the top right hand corner eventually short circuit, an error in the manufacturing process of the positive terminal tab (high welding bars formed during the ultra sonic welding process) caused the tab to breach both the insulation tape and the separator. This also led to short circuit and unavoidable CABOOMING! (lol)
These are the two main issues that they confirmed as the reasons for the catastrophic experience of customers of the Note 7 last year.
http://www.androidauthority.com/samsung-finally-tells-us-galaxy-note-7-phones-catching-fire-744538/?utm_source=&utm_medium=gplus

we all knew it was the battery.

Techm8:
we all knew it was the battery.

You mean suspected?

I've always been apprehensive of this development in the evolution of technology. Poor and less-thorough manufacturing. Sammy is really guilty of the rat race. Always trying to outrun their shadow.

I really believe we shouldn't have gone past the s6/note5 yet. Damn phones are next gen. Hurrying through the n7 is just pushing themselves too hard. Relax and spend proper time in R/D. How hard can that be?

Their integrity and openness is laudable though.

I wish them a successful year ahead.

Brigance:
I've always been apprehensive of this development in the evolution of technology. Poor and less-thorough manufacturing. Sammy is really guilty of the rat race. Always trying to outrun their shadow.

I really believe we shouldn't have gone past the s6/note5 yet. Damn phones are next gen. Hurrying through the n7 is just pushing themselves too hard. Relax and spend proper time in R/D. How hard can that be?

Their integrity and openness is laudable though.

I wish them a successful year ahead.

You are absolutely correct.