[Device Support] No output on display for AK400 DIGITAL SE (ID 3633:0001)

[SalixSorbus]

Hi,

I am using the DeepCool AK400 DIGITAL SE cooler. The application starts correctly, detects the device as A400-DIGITAL, and shows that it is updating data in the terminal. However, the physical display on the cooler remains blank.

Environment:

• OS: Fedora Linux 43
• CPU: AMD Ryzen 5 9600X
• GPU: AMD Radeon RX 580 2048SP
• Device ID: 3633:0001 (DeepCool A400-DIGITAL)

Terminal Output:

sudo ./deepcool-digital-linux 
--- Deepcool Digital Linux ---
CPU MON.: AMD Ryzen 5 9600X 6-Core Processor
GPU MON.: AMD Radeon RX 580 2048SP
-----
Device found: A400-DIGITAL
Supported modes: auto cpu_temp cpu_usage [default: cpu_temp]
-----
DISP. MODE: cpu_temp
TEMP. UNIT: °C
ALARM:      off
-----
Update interval: 1s

Press Ctrl+C to terminate

LSUSB Details:

Bus 001 Device 006: ID 3633:0001 DeepCool A400-DIGITAL
Device Descriptor:
  idVendor           0x3633 DeepCool
  idProduct          0x0001 A400-DIGITAL
  bcdDevice            1.01
  iManufacturer           1 DeepCool
  iProduct                2 A400-DIGITAL
  ...
      Endpoint Descriptor:
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
      Endpoint Descriptor:
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            3
          Transfer Type            Interrupt

Strace Analysis

I ran the tool with strace -f -e trace=ioctl,write.
The output shows that data packets (64 bytes each) are being successfully written to the device file descriptor (FD 3) without any errors:

ioctl(3, HIDIOCGRDESCSIZE or HIDIOCGVERSION, 0x7fff94ad9414) = 0
write(3, "\20\252\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 64) = 64
write(3, "\20\23\1\0\4\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 64) = 64

trace.log

Since the writes are successful but the display is not updating, it confirms that the AK400 DIGITAL SE expects a different data protocol or a different initialization sequence than the standard AK400 model.

Additional context

The device is recognized, but it seems like the data protocol or the HID reports for the SE version might differ from the standard AK400 DIGITAL supported by this tool.

• I do not have access to a Windows installation, so I cannot capture USB traffic from the official DeepCool software using Wireshark/USBPcap.
• I am looking for alternative ways to debug this on Linux.

Questions for the Maintainer:

• Are there any specific debug logs or environment variables I can enable to provide more information on why the data isn't reaching the display?
• Could this be related to the SE version specifically, even though the Product ID is detected as 0001?

[Nortank12]

Hi!

• Are there any specific debug logs or environment variables I can enable to provide more information on why the data isn't reaching the display?

If you're okay with using a Windows VM, you can either use a hypervisor or the dockurr/windows Docker image by providing the following environment variable inside the compose.yaml file:

services:
  windows:
    image: dockurr/windows
    environment:
      ARGUMENTS: "-device usb-host,vendorid=0x3633,productid=0x0001"
      ...

This will pass your device to the VM, allowing you to install DeepCool's software and capture the data packets. Note that the CPU temperature may be stuck at 0.

• Could this be related to the SE version specifically, even though the Product ID is detected as 0001?

It could also be an issue with your machine, as different devices (that require different packets) are using different product IDs. You might try booting a different distro (Arch or Debian based) from USB and try using the program directly. It should work.

[SalixSorbus]

I have successfully captured the USB traffic using Wireshark (USBPcap) on a Windows VM (see zip).
CPU temperature actually was stuck at 0, as you noted.

Please let me know if you need any further captures or specific tests!

pcapng.zip

[SalixSorbus]

You might try booting a different distro (Arch or Debian based) from USB and try using the program directly. It should work.

Today I tried to run a fresh Ubuntu distro from a USB. Same result as with Fedora, which is pretty new actually.

[Nortank12]

Very interesting indeed. I have checked the packets you sent, and they use a completely different format, although your device shares its product ID with the regular AK400 DIGITAL (see here).
I am not sure why did Deepcool decide this way but it does not seem to make sense. I will try to look into it this week and further analyze the packets.

[SalixSorbus]

Great job! I tested the changes and they fixed the issue. Huge thanks to @v1nvn for the solution and to @Nortank12 for the project!