FAQ¶
| Q | A |
|---|---|
| Can not boot up | 1. Check that the power adapter is tightly connected, and the voltage is within the acceptable range of 12–20 V (15–20 V recommended). 2. Try disconnecting the power adapter for a few seconds, then uninstall the RTC battery. Wait for at least 30 seconds, then reinstall the RTC battery and connect the power adapter. Turn on the LattePanda again. |
| Suddenly shuts down or restarts while running | Ensure that the power adapter meets the minimum requirements: 120 W or above for DC power input (the attached 180 W adapter is recommended), or USB-C PD 20 V at 100 W or above. Sigma 2 detects the PD adapter's wattage at power-on and adjusts the processor's power limits (PL1 / PL2) accordingly, so a 45 W or 65 W PD adapter limits performance instead of causing shutdowns — but an unstable or under-specified power supply can still lead to sudden shutdowns or restarts. For details, see Power Options. |
| No screen output | 1. Re-tighten the display cable and wait a few minutes until the system starts completely. 2. If there is no picture when using a Type-C display, please try an HDMI display to test. |
| Takes a long time to boot | Confirm the voltage of the RTC battery is enough. Low voltage or no battery will cause the operating system to take too long to boot. |
| Cooling fan doesn't start | 1. The default setting is that the fan automatically starts when the temperature reaches the startup threshold. 2. Check the BIOS fan settings and change the cooling fan temperature setting. |
| Access BIOS setup | Short press the power button and repeatedly press the DEL key on the keyboard until you see the BIOS Setup Menu. To select a bootable device after pressing the power button, continuously press the F7 key. |
| Auto Power-on doesn't work | Check that the DIP switch for Auto Power-ON is set to ON. |
| Why does the fan sometimes keep spinning in sleep mode — the screen turns off but the fan keeps running? | LattePanda Sigma 2 uses the Intel Panther Lake processor, which supports only Modern Standby (S0 low-power idle); the traditional S3 sleep state is not supported. Entering Modern Standby requires PCIe devices to signal through the CLKREQ pin — the onboard OCuLink connector does not provide this pin, so a PCIe device connected via OCuLink may prevent the system from entering Modern Standby: only the display turns off while the fan keeps running. For details, please refer to the OCuLink Connector section. |
| Why does Sigma 2 occasionally wake up briefly during Modern Standby — the fan spins up without the screen turning on — and then go back to sleep? | During Modern Standby, background maintenance tasks and connected-standby updates can briefly wake the system without turning on the display. Once the tasks are complete, the system automatically re-enters Modern Standby. This is why you may occasionally notice the fan suddenly spinning with no display output, then stopping again after a while. This is normal behavior, not a malfunction. |
| Performance seems lower when powered by a USB Type-C PD adapter | This is expected. LattePanda Sigma 2 detects the PD adapter's maximum wattage at power-on and adjusts the processor's power limits (PL1 / PL2) accordingly — a 45W or 65W PD adapter results in lower performance than the DC jack. For full performance, use the attached DC power adapter. For details, please refer to the PD Adapter Wattage and Performance section. |
| Local AI service is not running | 1. Make sure you are using the pre-installed Ubuntu OS on the attached SSD. 2. Double-click the 🔮 Start AI Assistant icon on the desktop and wait until the terminal shows ✅ AI services are ready.3. Check whether the local inference API is online: curl http://localhost:8080/v3/models.For more details, please refer to Local AI Quick Start and the README.md file on the desktop. |
If you have any problem when using LattePanda Sigma 2, please feel free to open your issue via LattePanda forum.
And we will really appreciate it if you can help to optimize the tutorials by committing tutorials or updates to the docs repo. Help users who have the same interests or meet problems like you do.
Appreciate your great support! And enjoy tinkering! ;)