Continued from [3DS Teardown (2)] Removing Lower Chassis
Nikkei Electronics Teardown Squad successfully tore down the lower chassis of the Nintendo 3DS and took out the main board from the chassis to carefully examine it.
We looked at the entire main board after removing the wireless LAN module printed with the "MITSUMI" mark, the slot for SD memory cards and so forth. On the back of the board, a chip printed with the characters "TOSHIBA" and "THGBM2G3PIFBAI8" ("I" is possibly "1") drew our attention. Judging from the model number, it seemed to be NAND flash memory. And, probably, it stores a system.
On the other hand, there were only few components embedded on the top side of the main board such as Texas Instruments Inc's "PAIC30108" and its peripheral circuits. Considering that there is a connection port for the lithium-ion (Li-ion) rechargeable battery on the back of the PAIC30108, it is probably a power supply chip.
After briefly examining the top and back sides of the main board, we realized an important thing: We could not find the main CPU. There was only one possibility left: under the slot for game cartridges. There were many passive components embedded on the back of the slot.
We managed to remove the slot, which was firmly fixed on the board, by using a soldering iron, etc. Then, the main CPU of the 3DS printed with the characters "Nintendo" and "ARM" appeared. A chip found next to the CPU was printed with "F JAPAN" and "M82M808080." It seemed to be Fujitsu Semiconductor Ltd's FCRAM.
We were relieved by finding the main CPU and began to disassemble the upper chassis, which contained the 3D LCD panel module viewable with the naked eye and was the main target of the teardown. By the way, we will tear down the touch-sensitive LCD panel module located in the lower chassis later, together with the 3D LCD panel module.