The position of the iPhone 3G's secondary battery posed a question to the engineers and Nikkei Electronics Teardown Squad (See related article 1). The next step is to remove the shield covering the main board and examine the board.

We started by looking over the upper side of the main board and found an LSI printed with Apple Inc's logo on the center right of the board. The characters printed on the LSI read "339S0036 ARM K4X1G163PC-DGC3."

A same type of LSI was used in the iPhone 2G though its model number was different (See related article 2). So, we deduced that it is an application processor with an ARM core.

On the lower left of the main board, there was an LSI printed with the letters "337S3394."

"Probably a baseband LSI," said an engineer.

Also, we found "SKY77340," a power amplifier module of Skyworks Solutions Inc, embedded on the lower right of the board.

"This (lower right part of the board) must be an RF circuit part for W-CDMA and GSM," said an engineer. "Probably, '338S0353' is a transmitter and receiver LSI for W-CDMA and GSM."

Next, we checked the lower side of the main board and found that not many parts were embedded on it. An engineer speculated that a heat radiation sheet was attached on the board because this side contacted with the Li-polymer secondary battery.

When we opened the part covered by a shield on the right side of the board, a chip marked "TOSHIBA R67657 JAPAN 0805 KCE" appeared.

"This must be Toshiba's flash memory," an engineer said.

iPhone Teardown Video (Part 3) (Japanese, 4:46)