Hypno Troubleshooting Guide
Last updated
Last updated
Hypno requires power from either the USB ports or your Eurorack case and will begin booting as soon as power is supplied. Hypno requires at least 2A @ 5V for USB power, or 330mA on the +12V rail from a Eurorack power supply. When using USB accessories such as UVC devices we recommend providing Hypno with 3A @ 5V for USB, and 500mA for +12V Eurorack power. Hypno can receive USB power from either its top USB-C port. For Hypno Kit we recommend you use the official Raspberry Pi3 Amp USB-C PSU plugged in to the Hypno Kit's rear USB-C port.
Isolate Hypno from all accessories (capture devices, MIDI controllers, etc.) before powering.
Hypno Original (CM3+): Ensure that the rear panel UPDATE switch is in the down position. Hypno will not boot if the switch is in the UPDATE position. Hypno displays one faint green LED when powered on in update mode.
Hypno Kit: Re-flash firmware onto the SD
If this doesn't work try to use your raspberry pi with an image from to verify your Pi is functional and booting correctly
Plug your USB power supply directly into a working wall socket, separate from any power strips.
Use a USB power supply with a minimum of 2A @ 5V, or 3A @ 5V if using accessories with Hypno.
Try another USB power supply.
Try another microUSB or USB-C cable, preferably one less than 6’ long.
Ensure that the ribbon cable is seated properly with all pins connected and the red stripe (-12V) is oriented according to the PCB printing.
Try another power header on your Eurorack bus board.
Try another ribbon cable. Hypno uses a 10-pin to 16-pin style ribbon cable.
Try powering Hypno using USB power instead
If you are unable to power Hypno after going through these steps, please contact support.
Isolate Hypno from all accessories (capture devices, MIDI controllers, etc.) before powering on
Plug your USB power supply directly into a working wall socket, separate from any power strips.
Use a USB power supply with a minimum of 1A (1 amp) @ 5V. When using USB accessories, we recommend 2A (2 amps) @ 5 volts.
Try a different USB power supply.
Try a different microUSB cable, preferably one less than 6’ long.
If using the front USB port for power, try using the side USB port instead.
Ensure that the ribbon cable is seated properly with all pins connected and the red stripe (-12V) is oriented according to the PCB printing.
Reseat the ribbon cable on the module and the bus board.
Try a different power header on your Eurorack bus board.
Try a different ribbon cable. Hypno uses a 10-pin to 16-pin style ribbon cable.
Try powering Hypno using USB power instead, using the steps above
As of firmware 2.1, Hypno displays the firmware version on video output upon booting.
Extract .gz archive (optional but speeds up flashing significantly)
Flip the switch on the rear left side of Hypno into the UPDATE position (not applicable for Hypno DIY)
Connect Hypno to a computer via the front USB port (for Hypno DIY insert MicroSD card into your computer).
Start Balena Etcher
Open downloaded .img in Etcher and follow the instructions (Hypno shows up as a “Compute Module” & may take a second to initialize)
Once flashing is complete, disconnect Hypno, put update switch into the down position (or eject SD card from computer and insert it into Hypno DIY) and power Hypno.
Make sure the update switch is in the down position (not applicable for Hypno DIY)
Cycle power (Hypno will not boot while in update mode)
If using a Compute Module unit (CM3/4) make sure the compute module is securely connected to the rest of the board and did not come loose during transit
Ensure that Hypno is isolated from all accessories
Connect Hypno directly to a computer using the provided USB-C cable with no hubs or adapters
Try another USB-C cable (cables < 6’ are recommended)
Attempt the update on another computer
If none of the above helps, attempt the EMMC test described in Section 8
Hypno has built in HDMI digital video output on the top side of the module. The composite video can be standard definition NTSC or PAL (480i/576i). It is not possible to use both outputs simultaneously; Hypno will automatically use the HDMI output if it is connected to an active display on boot. If no display is detected, it will default to composite.
If you intend to use the Hypno HDMI output, please plug an HDMI cable into your display (TV, monitor, projector, caputre-card, etc...), power your display on, and plug the other end of the HDMI cable into the Hypno before powering the Hypno on.
Connect Hypno to an actively powered HDMI display or capture device before turning the module on
Try another HDMI cable, preferably less than 15’ long
Try another active HDMI display
Ensure Hypno is not connected to an HDMI display, or else it will default to HDMI output. Only one hardware video output may be used at a time.
Hypno is capable of broadcasting NDI video from its front micro USB port (or Ethernet/WiFi for properly equipped Hypno DIY). This allows you to capture, stream and monitor Hypno’s output directly on a Mac or PC without additional hardware. With no HDMI output connected, Hypno will output 720x480 over NDI. If the HDMI is connected, the NDI output resolution will match the resolution of the HDMI output.
Hypno Kit built with a Raspberry Pi 4 will not initialize NDI unless an HDMI cable is connected and transmitting signal when the Hypno is powered on.
Install NDI 5 Tools.
Connect Hypno to your PC using a microUSB cable from the front USB port (or Ethernet/WiFi for properly equipped Hypno DIY) and allow Windows to automatically install drivers*
Reboot your PC
Open NDI Tools “Studio Monitor”
Click the top left hamburger menu and select Hypno:main
Hypno should now be viewable from Studio Monitor
Install NDI 5 Tools for Mac (installer automatically installs Studio Monitor)
Connect Hypno to your Mac using a microUSB cable from the front USB port (or Ethernet/WiFi for properly equipped Hypno DIY) and allow your OS a moment to recognize the device
Open NDI Tools “Studio Monitor”
Click the top left hamburger menu and select Hypno:main
Hypno should now be viewable from Studio Monitor
Some USB ports may not deliver enough power for Hypno to run on alone. Try connecting Hypno to a separate power source, such as Eurorack power or the side USB port. Verify external power sources are suitable as described in Section 1.
If you have an original Hypno (non-Kit), confirm that it is connected to your computer via the module’s front USB port. This is the only port capable of supporting data
Try another cable, preferably less than 6’ long
Disable VPNs and/or Firewalls.
Hypno Kit built with a Raspberry Pi 4 will not initialize NDI unless an HDMI cable is connected and transmitting signal when the Hypno is powered on.
In some cases, disabling Windows Defender Firewall for Public Networks resolved connectivity issues. Not recommended when connected to public Wi-Fi networks (school, work, coffee shop).
As of firmware revision 2.0, Hypno can accept video input from UVC compliant capture devices and webcams (USB 2.0, MJPEG compressed output) through its front micro USB port (or rear USB-A ports on properly equipped Hypno DIY). A USB OTG (microUSB adapter) cable is required to connect USB accessories (not for Hypno DIY). In general, Hypno should work with any webcam or capture card that is:
UVC compliant
USB 2.0
Supports an MJPEG compressed output mode
NOTE: Regarding USB hubs, please use a supported hub and leave generous headroom in the available current of your power supply or hub, otherwise you may damage your device or peripherals.
Connect your USB 2.0 UVC device to a USB OTG cable (microUSB adapter) and plug this into Hypno’s front USB port (not applicable for Hypno DIY)
Hypno will automatically recognize compatible devices and switch Shape A to the video input
Transform controls for your shape remain intact and may be used to modify the video input
Verify the capture/webcam device is UVC compatible
Connect your peripherals directly to Hypno using a USB OTG (microUSB) adapter, avoid using hubs.
Test the capture card using a computer.
Test the USB OTG adapter with another device, such as a USB webcam, USB MIDI controller, or different video capture card.
In rare cases it may be necessary to reflash the Hypno firmware. See Section 2 for instructions.
Try another power supply. We recommend a 2A 5V power supply or better when utilizing USB accessories.
Try another USB cable, 6’ or shorter.
Ensure that your case power is sufficient for Hypno. Hypno can require up to 500mA from the +12V rail when using video input. You can check your system’s power needs by using Modular Grid.
Try USB power if you’re unable to eliminate your Eurorack power supply as a potential cause.
Verify the capture card’s functionality using a computer.
Test the USB OTG adapter with another device, if you have one. This can be a USB video capture device, a USB webcam, or a USB MIDI controller.
In rare cases it may be necessary to reflash the Hypno firmware. See Section 2 for instructions.
Try another HDMI cable.
Try another HDMI source.
Ensure the source’s resolution is within the specifications of the capture device.
Test the HDMI source on an HDMI display
Hypno is equipped with USB-MIDI Host capability, meaning it can accept incoming MIDI CC (continuous controller) and note messages from Class Compliant USB-MIDI devices, such as MIDI keyboards and controllers, as well as some grooveboxes and synthesizers. Connecting a MIDI device requires a USB OTG (microUSB adapter) cable (not for Hypno DIY). Note that host to host MIDI connections, such as between Hypno and a computer, are not currently supported.
Verify the MIDI device is capable of Class Compliant USB-MIDI
Verify the MIDI device is transmitting on MIDI channel 16
Verify the MIDI device is mapped to the correct CC parameters in the MIDI implementation chart
Try another USB cable
Try another OTG adapter (not applicable for Hypno DIY)
Update Hypno to the latest firmware version. See Section 2.
Hypno is equipped with 6 knobs, 2 sliders, 3 buttons, 9 minijack inputs for CV. Hypno’s CV inputs accept a range of +5V to -5V, voltages above or below +/-5V range will be clipped. Incoming CV is summed with the parameter’s knob position.
Disconnect any CV sources from the corresponding knob
Disconnect any MIDI devices
Isolate Hypno from all other accessories
Reboot Hypno
Change the position of the corresponding knob
Try another patch cable
Verify the CV source is sending CV by patching it to another module
Update Hypno to the latest firmware
Reboot Hypno.
If the issues persists, refer to Section 1 for power and boot troubleshooting.
If you hear a buzz or hum when Hypno is connected to your computer, you may have a ground loop. Ground loops are a common cause of noise, hum, and interference in audio and video devices when interconnected devices are receiving power from separate sources. If you’re experiencing ground loop noise, some of the following suggestions may help you identify or eliminate the source.
Plug your Hypno, computer, computer accessories, video capture devices, audio interface, CV devices, and anything else that is physically interconnected, into the same power strip/conditioner (provided that the power strip/conditioner has enough sockets and can safely supply the required power for the aforementioned devices).
Power Hypno using an AC to USB power brick (USB wall outlet adapter), with at least 1A output, connected to the module’s side microUSB port.
Power any audio interfaces through its mains connection, as opposed to USB bus power.
If the noise is still present, try simplifying your setup until you pinpoint the culprit by process of elimination.
USB ground loop isolators may help mitigate ground loops, especially if the device causing trouble in your system is battery powered with no means of direct mains connection.
Additionally, you can help eliminate noise and other interference in your setup by using balanced audio cables wherever possible, power conditioners in place of power strips, and avoiding running audio or video cables parallel to power cables.
Due to the complexity of audio-visual setups we can’t provide formal technical support for ground loops, but feel free to post about your issue in this thread if you need help.
While Hypno is powered off, take the module out of its enclosure and flip the rear panel switch into the "UPDATE" position
While continuing to leave Hypno unpowered, connect the module to an active HDMI display (a TV or monitor that is currently ON) with a working HDMI cable.
Connect Hypno's front microUSB port to a Mac or PC and open Balena Etcher.
You should see the rainbow splash screen and some messages scrolling in the console on your HDMI display connected to Hypno.
Verify a powered display was connected BEFORE connecting Hypno to a computer, with no other power sources connected.
Attempt to reseat the Compute Module using the directions below.
Attempt to reseat the Compute Module using the directions below.
If that doesn't work and you are still getting the above error, your compute module may be defective please contact support@sleepycircuits.com
PRACTICE STATIC AWARENESS: This procedure requires you to handle electrostatic-sensitive parts. Failure to follow these recommendations will result in part failure that is not covered by manufacturer warranties.
Touch metal to discharge any static buildup BEFORE handing any Circuits Boards (PCBs)
Handle circuit boards by their edges!
Avoid doing any of these steps on carpeting or while wearing your fluffy clothing as things these tend to charge humans with static.
Use a static mat and wristband if available
Please read this page completely before attempting!
It is important to follow every step in this procedure in order exactly as described.
Take Hypno out of its enclosure or your Eurorack case and place it on a table face down, with the Compute Module socket facing you. Before proceeding, touch something metal to discharge any built-up static electricity.
Using both hands to hold the module steady, use your index fingers to pull the two small latches gently outward, the Compute Module should pop up.
Carefully hold the sides of the PCB and pull the Compute Module from the socket, avoid touching any of the components on the board.
Inspect the board for any obvious damage.
Gently place the Compute Module back into the socket until the pins are evenly seated.
Hold the Compute Module down in place while you press the latches back into place.
Put Hypno back into its enclosure or Eurorack case and test to see if it works now
Verify your system’s power requirements and supply specifications to ensure you have enough power for all of your modules. Use to accurately plan your modular’s power needs, but make sure you leave some headroom as modular grid isn't 100% accurate, particularly with modules first powering on.
Verify your system’s power requirements and supply specifications to ensure you have enough power for all of your modules. Use to accurately gauge your modular’s power needs.
Hypno requires the Balena Etcher program to write new firmware images to the EMMC. Download the correct installation for your operating system from their website:
The latest firmware images for Hypno can always be found at on the .
Download and install
Download the
Remove Hypno from its enclosure. This video shows you how: . For Hypno DIY see (and reverse the process shown).
In some cases, Windows users will need to install and run RPiboot for the Compute module to be recognized. Download RPiboot from the Raspberry Pi foundation:
with any issues not described here, or if you need further assistance updating.
Please follow the directions for building and using rpiboot found on this page:
Verify that Hypno and your TV are using the same television standard, NTSC or PAL. Firmware images are available for both, install the one that matches your display found .
Before continuing this section, see the segment of the Hypno Manual.
*On some systems it is necessary to install the RNDIS driver. Please follow this detailed guide:
Install the RNDIS driver, if you have not already done so
Check out the discussion on NDI in Windows on our forum:
Or NDI on Mac:
UVC input is available on Hypno firmware 2.0 or later. We recommend always updating to the
Extended controls for the video input, like luma keying and aspect ratio, are available using a new Page in the Hypno UI. This is detailed in the .
Install the onto the module, as described in Section 2 of this manual.
We’ve compiled a running list of compatible USB accessories on the forum:
For Hypno DIY see (and reverse the process shown).
Some units produced in Dec 2020 and before may experience a small amount of jitter due to a minor hardware flaw. Affected units are eligible for free repair under our voluntary recall. for details.
Load the into Balena and select Hypno as the target, this will trigger the module to begin initializing.
If reseating the Compute Module does not resolve your issue, please for a resolution.
