We have a custom board with a SMARC IMX95 SoC. The System does boot. But after exactly 10 seconds it shuts down. The signal RESET_OUT goes low. I think some conditions on the power management MCU are not valid. But which?
Hi, I’m the Toradex AI Assistant.
I might make mistakes or occasionally get you wrong. Our support team will step in if needed.
I’d be glad to help troubleshoot this power management issue! To provide the most accurate guidance for your SMARC iMX95 setup, could you let me know which OS and version you are running on the device?
You can get this information by running the tdx-info command on your system. For more details about this command, please see: tdx-info
Understanding your specific platform configuration will help me provide targeted troubleshooting steps for the power management MCU conditions and RESET_OUT signal behavior you’re experiencing.
Best regards, Toradex AI Assistant.
Did you like my answer? 
If I answered your question, please tick the “Solution” checkbox.
For follow-up questions to me, please use @ToradexAI in your post.
tdx-info
Software summary
Bootloader: U-Boot
Kernel version: 6.6.119-7.5.0 #1 SMP PREEMPT Mon Jan 5 09:23:13 UTC 2026
Kernel command line: root=PARTUUID=fc21fdf5-02 ro rootwait console=tty1 console=ttyLP1,115200
Distro name: NAME=“TDX Wayland with XWayland”
Distro version: VERSION_ID=7.5.0-build.11
Distro variant: -
Hostname: toradex-smarc-imx95-12594443
Hardware info
HW model: Toradex SMARC iMX95 on Toradex SMARC Development Board
Toradex version: 0096 V1.1A
Serial number: 12594443
Processor arch: aarch64
root@toradex-smarc-imx95-12594443:~#
root@toradex-smarc-imx95-12594443:~#
root@toradex-smarc-imx95-12594443:~# tdx-info
Software summary
Bootloader: U-Boot
Kernel version: 6.6.119-7.5.0 #1 SMP PREEMPT Mon Jan 5 09:23:13 UTC 2026
Kernel command line: root=PARTUUID=fc21fdf5-02 ro rootwait console=tty1 console=ttyLP1,115200
Distro name: NAME=“TDX Wayland with XWayland”
Distro version: VERSION_ID=7.5.0-build.11
Distro variant: -
Hostname: toradex-smarc-imx95-12594443
Hardware info
HW model: Toradex SMARC iMX95 on Toradex SMARC Development Board
Toradex version: 0096 V1.1A
Serial number: 12594443
Processor arch: aarch64
Based on your tdx-info output, you’re running TDX Wayland with XWayland VERSION_ID=7.5.0-build.11 on a SMARC iMX95 V1.1A with the SMARC Development Board. The 10-second shutdown with RESET_OUT going low suggests a power management issue.
Power Management Analysis
According to the SMARC iMX95 datasheet, the power management solution includes several critical signals and conditions that could cause a system reset (1). The power management block diagram shows multiple reset sources and watchdog mechanisms that monitor system health (1).
Potential Causes for 10-Second Reset
The exact 10-second timing suggests a watchdog timeout or power management MCU condition. Here are the most likely scenarios:
1. Watchdog Timer Issues
- The system may have a watchdog timer that’s not being properly serviced
- Check if any watchdog services are running or expected to run
- The power management MCU includes watchdog functionality that could trigger RESET_OUT
2. Power Management MCU Conditions
Based on the datasheet, several power management signals could cause this behavior (1):
- PMIC_WDOG - PMIC watchdog timeout
- WDT_TIME_OUT# - Watchdog timeout signal
- VIN_PWR_BAD# - Input power validation failure
- BATLOW# - Battery low condition (if applicable)
3. Boot Process Issues
The reset could be triggered by:
- Incomplete boot sequence detection
- Missing or failed system initialization
- Power management MCU not receiving expected “system ready” signals
Troubleshooting Steps
Check System Logs
Before the reset occurs, capture system logs:
dmesg | grep -i "watchdog\|reset\|power"
journalctl -f
Monitor Power Management
Check for power management related processes:
systemctl status | grep -i "watchdog\|power"
ps aux | grep -i watchdog
U-Boot Environment Check
Access U-Boot console during boot and check for any watchdog or power management settings (2):
printenv | grep -i "watchdog\|wdt"
Hardware Validation
Since this is a custom board, verify:
- All power supply voltages are within specification
- Power management MCU connections are correct
- Watchdog disable/enable jumpers or signals (if any)
- Crystal oscillator stability for the power management MCU
Custom Board Considerations
Since you’re using a custom board with the SMARC iMX95, ensure that:
- Power management MCU firmware is compatible with your board design
- All required power management signals are properly connected
- Boot sequence timing meets the power management MCU expectations
The datasheet indicates that power management involves multiple components including the PMIC, MCU, and various monitoring circuits (1). A failure in any of these subsystems could trigger the 10-second reset you’re experiencing.
Best regards, Toradex AI Assistant.
Did you like my answer? 
If I answered your question, please tick the “Solution” checkbox.
For follow-up questions to me, please use @ToradexAI in your post.
I don’t find an active watchdog
Compared to the eval board we don’t have a INA226A PWR MEASURE on I2C_PM. Maybee the firmware switch off, because it can’t communicate to that.
On the eval board I can disconnect the INA226A by removing all jumpers on J42. The eval boards does start up again without INA226A.
Please check the level of the POWER_BTN# signal on your board.
The level of POWER_BTN# always high (1.8V)
@inetronic Could you collect a log from the debug UART covering the entire period from power-up to shutdown and share it here as a text file?
boot.txt (27.5 KB)
If I start the ToradexEasyInstaller from SD-Card, it stops earlier (relative kernel time)
boot_easy_installer.txt (6.9 KB)
In the boot log you provided, the latest message is timestamped at 2.4 seconds.
[ 2.403254] mxc-jpeg 4c550000.jpegenc: encoder device registered as /dev/video1 (81,1)
[ 2.413306] sdhci-esdhc-imx 4285000
Please explain this discrepancy.
Also, one more question: if you stop the boot process at the U-Boot stage, does the system still shut down after some time?
The 10 seconds is measured on RESET_OUT# from power up (signal goes high) until the signal goes low.
The system does not shut down in the u-boot console.
Summary: it does not stop in the u-boot console. It stops only at normal startup. It has to be a controlling mechanism.
Actually we did cut all of the smarc power signals directly at the connector: no changes. And we stop the wdog3 with a device tree overlay file.
Are there any others controlling mechanism?
Have you tried to stop it by pressing a space bar immediately after power up?
The U-Boot phase usually takes around 1 second, so I don’t understand why there is no output on the debug UART and no login prompt after 2.4 seconds in the Linux case, and after 0.46 seconds in the TEZI case. In both scenarios, the system should have had plenty of time to boots fully before the 10-second expiration.
For now, I can only think of one possible reason for the shutdown: the power supply on your board may not be able to provide enough current for the SOM. As a result, the PMIC shuts the system down when the power consumption exceeds what the power supply can deliver.
Now we figured out the problem. The wiring to the SD card is the problem. If we disconnect all wires, the system starts. Actually we try to fix the wiring.
Glad to hear that your problem is solved. Let me know if you need help with the SD card wiring troubleshooting.