# Cube Orange + / Config Error: Failed to update IOMCU firmware

**URL:** <https://discuss.cubepilot.org/t/cube-orange-config-error-failed-to-update-iomcu-firmware/17095>\
**Category:** Cube Autopilot\
**Created:** [5 November 2025 18:51 UTC](https://discuss.cubepilot.org/t/cube-orange-config-error-failed-to-update-iomcu-firmware/17095 "2025-11-05T18:51:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Aaron](https://discuss.cubepilot.org/user_avatar/discuss.cubepilot.org/aaron/32/9297_2.png) [@Aaron](https://discuss.cubepilot.org/u/Aaron)\
**Post date:** [5 November 2025 18:51 UTC](https://discuss.cubepilot.org/t/cube-orange-config-error-failed-to-update-iomcu-firmware/17095/1 "2025-11-05T18:51:46Z")

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Hello!

I am currently in the process of putting together a build with a Cube Orange + with Standard ADSB Carrier.  
I plugged into MP and I am getting a warning  
Config Error: Failed to update IOMCU firmware  
I set BRD\_IO\_ENABLE to option 2 and then I receive  
PreArm: IOMCU is unhealthy

I have tried re installing the firmware a few times but still no change.

Notes:

- Solid orange light when plugging into either the carrier or the cube orange +
- Carrier is Rev E
- Holding the safety switch down while plugging in gives me a solid green and a rapidly flashing orange light
- Holding the safety switch down while plugging in does not seemingly actually put me in DFU. Mavlink connections are still available in MP
- I am able to connect to MP and configure parameters
- I am able to see my internal compass
- The carrier board powers peripherals however I have not attempted anything past this.
- PDB is sending 5v clean to the flight controller as well as voltage and current sense and ground.
- Seemingly the firmware flashes without issues or at least that’s what the messages tell me.

I have some familiarity with these things but not this specific issue. I have successfully fixed a few devices with guidance from the communities but more or less trying to get a feel for how feasible or realistic it is vs sending it in or buying another autopilot. I am looking at quite a few of the same issue with no real solutions yet. I have gotten close to similar with discussions such as this one:

> [@How to activate DFU Mode on Cube Orange+](https://discuss.cubepilot.org/t/how-to-activate-dfu-mode-on-cube-orange/12704):
>
> Hello, I currently have a bad bootloader on my Cube Orange +. To upload a new bootloader, I want to put it in DFU mode. From what I have read online, the only way to do this is to break open the case and manually pull up the BOOT0 line on power up. Is there any way to enter DFU mode without breaking into the case, like with an ST-link or the BlackMagic Probe ([https://black-magic.org/](https://black-magic.org/))? I do have access to the IO and FMU Debug ports through the ADS-B Carrier board.

I appreciate any and all help. And if the answer is simply to landfill it then so be it.