Internals

Opening up the PSU reveals a not-too-cramped interior. We can instantly notice that the same PCB is used not only for the 850 W and potentially 750 W versions for the Atmos, but are possibly also featured on some (maybe other series) 650 and 550 W units.


The Atmos 850 W is based on a full bridge topology with a series resonant converter design which is quite common for power supplies of similar efficiency ratings. The CM6901T6 SRC controller is used for the PSU. It is located on the back. And yes, the back side of the PCB is indeed green.


All of the connectors and coils are covered in dark rubber. While a bit more cumbersome to take apart, this is typically a robust insurance against unwanted coil whine.


While part of the primary filtering (two y caps and one x cap) is soldered right on the AC power socket, the remaining components, including a MOV, two additional y capacitors and a couple of chokes are on the main PCB.


Further down the line we have dual diode bridges squeezed between heatsinks.


The +3.3 V and +5 V rails are delivered via a DC-DC converter board. At the heart of it we find the APW7159C PWM controller.


The connector daughterboard includes some polymer and electrolytic (Nippon Chemi-Con KHZ series) capacitors for filtering. An additional three Nichicon capacitors can be found on the main PCB right next to the connector board.


For the main (bulk) capacitor we have a single 680 uF / 400 V rated capacitor from the same Nippon Chemi-Con (this time the KMR series)


The IN1S429I-DCG chip is used as the supervisor, which lacks any public documentation.

The overall build and assembly quality is very good.


The Atmos 850 includes the Hong Hua HA1225H12F-Z 120 mm fan that's rated for up to 2200 RPM. It is connected by a simple dual-wire connector and partially covered by a plastic shroud to better distribute the air flow across the PSU internals. As mentioned in the specs, the fan features a fluid dynamic bearing.