Continued from [3DS Teardown (1)] Looking Into 3D Display
After checking the 3D display of the Nintendo 3DS, we started to tear down its main body by disassembling the lower chassis, in which we thought the main board was located.
This is normally the most difficult task when we break down an electronic device. Especially, we had trouble in disassembling Apple Inc's iPhone and iPad because their upper and lower chassis are fitted into each other without using screws.
However, we did not have such a problem with the 3DS. There were four screws on the lower chassis, and they could be removed by using a cross head screwdriver. We thought that the teardown of the 3DS would go smoothly.
After removing the four screws, a lithium-ion (Li-ion) rechargeable battery appeared. Its capacity was 1,300mAh. According to Nintendo, the 3DS can be continuously used for three to five hours when a game for the 3DS is being played and five to eight hours when a game for the Nintendo DS is being played.
It takes about three and a half hours to charge the battery. We wondered if the screws are supposed to be removed by the user or a shop clerk for replacing the battery.
In any case, we moved on because there were many things left to be torn down. And we succeeded in breaking down the lower chassis without any major trouble.
Then, we examined the main board. It looked tidy probably because the 3DS is a machine dedicated to gaming.
On the main board, the character "MITSUMI," which was seen under the slot for game cartridges, drew our attention. From the model number, "DWM-W028," we estimated it to be Mitsumi Electric Co Ltd's wireless LAN module supporting IEEE802.11b/g.
The slot for SD memory cards was also printed with the character "MITSUMI," suggesting the possibility that Mitsumi Electric is supplying many electronic components for the 3DS as it does for Nintendo's previous portable game consoles.
At this point, we could not find the main CPU. We began to remove the main board from the chassis to carefully examine it.