A Look Inside

Taking apart the DS420j isn't difficult. The top and side cover is metal, and the same goes for the chassis. Only the front cover is made out of plastic.


This is the board with the LED indicator.


The mainboard is small and has the RAM directly soldered on, which means it is unfortunately not upgradable.


The Realtek CPU has a low TDP, so there is no need for active cooling.


This looks to be a six-phase VRM, with the PWM controller located in the center.


This is a Macronix MX25L12833F serial flash multi I/O device. Some of you might wonder what a serial flash device is. The flash memory is used for storing executable code, which is downloaded to the RAM from the serial Flash during the power-up phase and executed by the processor. The serial flash code is write-protected—it is used to store the BIOS code.


In the photo above are an SK34C Schottky Barrier Diode (SBR), a polymer cap in the middle, and a 4435GM FET on the left.


Part of the operating system is stored in the IC shown above.


An ASMedia asm1061 SATA controller.


This is a magnetic module. It is mostly used for isolation purposes.


There aren't many caps on the mainboard. They are polymers and provided by good manufacturers, though.


The SATA expansion card.


A view of the I/O ports. With the chassis removed, the reset button can be seen now.


The two fans are by Y.S Tech, and their model number is FD128020HL. They measure 80 mm across and can easily be removed if you want to clean or replace them. Finally, they use double ball bearings, which increases their durability under even tough operating conditions.