Opening the unit will probably void the warranty. Any attempt to perform this modification without the required skills or following precautions can easily damage the unit beyond repair. I cannot be held responsible for any damage. You do this at your own risk.
The unit contains lethal mains voltage and ESD sensitive components. Proper safety precautions and ESD rules must be strictly followed.
Fig.1 ATEM switcher's upper cover removed by removing its 10 black Phillips screws. Here one of the two original noisy fans is already removed.
The unit is initially fairly silent, but after a while, the fans will run at full throttle, and the noise becomes unpleasant. Too much for my ears - for prolonged use. This is not a huge problem if the unit is stowed away inside a rack. But if you work in close proximity, then the situation is more severe.
I found at least another unhappy user with a silencing solution:
This idea works probably OK, but I cannot directly recommend it - you risk some serious things:
Frankly speaking, the original thermal design of this unit is - poor. The design seems to go back a couple of years, my recently purchased unit (May/2020), is manufactured in 2016. It seems that the design has been static since the introduction, or then BM is selling old stock... Please drop me a line if your unit's interior differs from this one.
The heavy number-crunching tasks (video processing) are taken care of by two power-hungry Xilinx FPGA's, hiding under the finned heatsinks on the main PCB, see Fig.1. These are the components that dissipate the majority of the heat. Their cooling relies solely on the fact that enough cool air is pushed through the fins via the rather small heatsinks. To make the flow as efficient as possible, there is an airflow controlling (plastic) viaduct mounted to the lid, see Fig.2.
The original (speed-controlled) 40mm fans are noisy, even at the lowest speeds. Unfortunately, due to the under-dimensioned heatsinks, the fans need to (and will) run after a while at full speed. This generates unpleasant and constant disturbing noise. Don't even dream of performing a voiceover when sitting close to this unit, or recording other faint sounds close to this unit.
Replacing the fans with ultra-silent Noctua fans is a straightforward process. Always unplug the unit from the mains whenever the cover is removed. Remove carefully the old fans by unscrewing them and unplugging their cables from the main PCB. Attach the Noctua fans in the same orientation (blowing outwards, and rotated so that the wires come out from the bottom). Do not use the screws that came with the Noctua fans, they will fit but are too long and will collide with the lid when its replaced. Use the fan fixing screws that came with the unit.
The electrical wires, and their order, are the same. But beware - the colors of the wires are different. Since the Noctua fans come with another type of connector, you need to cut these away and reuse the connectors from the removed fans. Since it is practically impossible to rewire the old connectors, cut them from the old fans, and leave an inch or two of the original wires. See Fig.3 as an example of proper wiring. Make sure to solder properly all wires before shirking the heat-shrink tubes. Table.1 has the colors and wire functions listed (only valid for the listed Noctua fan):
Noctua wire color
Original fan wire colors
Speed tacho out
Speed control PWM
Table.1 Fanl cable colors and functions
My initial test was performed with two Noctua fans, but types without the PWM speed control (just happened to have two of them). Such fans always run at full speed. Unfortunately, even these very silent fans produced quite loud noise at full speed, but the noise was more pleasant. The air exhaust ports in the top lid consists of small holes that make the exhaust air very turbulent. This produces additional noise. You can hear the difference by placing the lid temporarily in place. To drill open these air holes is not an option.
After replacing the fans with the correct type Noctua PWM fans (see Fig.4, Fig.5 shows the fans after installation) the unit was initially extremely quiet. But even these fans must run at full speed when the unit heats up. The video mixer adjusts the fan speeds according to the FPGA temperature(s), and the new fans have similar flow rates as the old ones. Something else had to be done.
Both the bottom and top covers are made of painted aluminum. Since aluminum is a good heat conductor it was obvious that conducting as much heat as possible from the FPGA's to the chassis - without removing the original air-cooling - was something to test.
This requires that you take apart the whole unit, mechanically modify some parts, and put it back again. This procedure took me many hours doing it carefully, step by step. Doing it again would be easier now knowing the tricks and procedures. I hope these instructions get you up to speed if you decide to do the modification.
This thermal modification consists of actually three modifications:
Fig.2 The air viaduct is essential for the cooling of the FPGA's. To prevent overheating, never run the unit for longer than a couple of minutes if the lid is open.
Fig.3 The colors differ but here is an example of the proper connection. Use heat-shrinkable tubing to guarantee goodisolation. Electrical tape is a no go.
Fig.4 This is the proper Noctua fan type to use. Make sure it is the PWM model!
Fig.5 Noctua fans after proper installation. Make sure that the fan cables don't interfere with the air viaduct in the lid, before closing the same. The locations of the plastic walls are indicated in the silk-screen on the PCB.
Fig.6 The noise measurements were made using a Zoom X99 recorder with a fixed volume setting and no LP filter, at a distance of 30cm.
TAKING THE UNIT APART
Fig.9 You might have to slightly bend the XLR-connector's locking brackets, to be able to pull them through the back panel holes. Bend them just as little as needed, they are brittle.
Fig.8 Remove all BCN-connector nuts and washers, as well as the XLR-conector's screws.
Fig.10 Heatsink holding sprockets seen from the underside. Here is also the 4mm thick themal gap fillers put into place.
Fig.11 Proper thermal paste.
Fig.12 Original air viaduct - removed from the top cover (6 screws removed).
Fig.13 Modified air viaduct with the centre part cut away to open a path all the way to the top cover inside surface.
Fig.14 Paint removed from the surface of the inside of the top cover, after the viaduct is put back.
Fig.15 Four cut-to-size layers of thermal gap filler is placed into position. Their thickness fills nicely the complete gap between the top of the heatsinks and the top cover.
It is time to reassemble everything now that all three (or at least modification 2) are performed.
REPLACING THE PARTS
Before closing the lid it is advisable to check the proper operation of the unit by powering it up and testing all functions. Before applying power it is advisable to double-check everything and compare the unit with the photos that you took before the disassembly. Connect the mains cable and at least one video source and preferably also a preview monitor. Do not touch any parts inside the unit when the lid is open and power is applied. Turn on the power and check that the unit wakes up normally and that both fans start to spin (slowly). Check that the unit works normally by using the front panel buttons and that there is an image on the small front panel display.
If all seems to be in order, turn off the power and proceed with closing the lid. Because the thermal gap filler is heavy and does not stick to the lid, the only easy and working way of closing it is to do it upside down.
Fig.16 External fixing plate and standoff. This plate has a double function in my system. The additional aluminum plate acts as a heatsink (yes - there is thermal paste between it ant the unit bottom), but also as a convenient standoff to elevate the unit about 10cm above the table surface.
Fig.17 The M3 screws that attached the unit to the bottom plate are so short that they cannot be tightened at high torque, and can, therefore, become loose. Locking the screws is a must, ordinary nail polish works great (any color would do :).
Fig.7 This modification requires that you take apart the whole unit, everything else than the front panel. In this picture its also taken apart - but for another non- relevant reason). Disassembly in not very complicated but you have to be very careful and follow proper ESD handling precautions. If you don't know what that word means, please don't attempt this modification.
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