Maker Tip: SBC misbehaving? Check your power supply!

by Bohdan Lechnowsky

Here at ameriDroid, we don't just sell SBCs. We use them in our everyday operations.

Yesterday's Issue

We had an issue with an ODROID-HC1 yesterday, one of the main components of our back-office database system, that has been in 24/7 operation for many months. Although we have automated backup processes backing up the systems daily, we weren't thrilled with the idea of having to redo some of our work from earlier in the day.

The problem presented itself by the HC1 rebooting itself for no apparent reason earlier in the day. Following that, the HC1's 2.5" HDD started making strange noises.  Further unexpected reboots occurred. It didn't occur to me at the time, but the problems coincided with when the octa-core processor on the HC1 was under heavy load.

Our Troubleshooting Steps (and our results)

1. Disconnect any unnecessary peripherals to see if one of those are causing the malfunction - our problem persisted after trying this.
2. Make an image of the OS on the microSD card as a safety net, and copy that image onto a second microSD card for testing.
3. Try the original and new microSD cards in a compatible system (in this case, that could be another HC1, or an HC2, XU4, MC1 Solo or XU3)
4. Try a different power supply.

When we performed step 1, we pulled the power and disconnected the Ethernet cable and the 2.5" HDD. The system booted, but it restarted within a minute or two for no apparent reason. The easiest way to see this is by watching the blue heartbeat LED. If it is off, that means that the boot media is not detected or the system is off. If it is solid blue, the OS is not responding. We'd get the heartbeat for a few seconds, and then the LED would turn off, go solid blue and then start the heartbeat again.

When we performed step 3, we first tried another HC1 without a 2.5" HDD attached. This time, the green LED (the SATA activity LED) was flashing and the red power LED would alternate between bright and dim. We tried removing the microSD and powering it on again without the microSD attached, and it showed the same effect.

Just to be thorough, we then tried on an XU4 with the boot selector switch set to microSD. The red power LED alternated between bright and dim. This is when it struck me that the power supply was probably not working correctly and not able to provide enough power to run the system.

At this point, I put the microSD back in the original HC1 with the hard drive attached, connected the Ethernet cable, and connected a new 5V/4A power supply. The system booted up with no problems on the original microSD!

Learning Point

When diagnosing SBC problems in the future, I'll switch steps 3 and 4 and see how that goes!

Also, because this system is often under a pretty heavy load, plus running a 2.5" HDD (hard drive), we upgraded this system so it now uses the 5V/6A power supply which provides 50% more capacity than the base 5V/4A power supply.