cRIO buzzing

our cRIO is making a weird buzzing noise, it wasn’t making it until recently, does anyone know what this means?

Are you positive that it’s the cRIO and not the PD? The boost converters in the PD are known to whine (especially with lower battery voltage).


The cRIO also could buzz during current limiting. Is the controller otherwise functional? Can you also check the voltage across the input (V and C).

we had a similar problem with the CRio “buzzing”

Battery voltage was low the CRio was only getting about 16v… which if i recall is under minimum voltage recommendation.

Either just change the batt see if that fixes it or get a multi-meter and check voltages…

If you’re seeing 16V on cRIO, please check the output of your battery. It would have to be pretty low for the voltage to drop, but I’d like to know what it was.

16V is symptomatic of either using one of the bad 2008 batteries or using a remarkably discharged battery.

With the bad 2008 batteries, the unloaded voltage may read good, but the loaded voltage will drop like a rock. Please measure it while it is attempting to power the robot.

Also, please confirm by attaching a known good battery.

We were running the robot around for about 20 min ish and it stopped working. noticed the CRio wasn’t on so we got the multimeter and the voltage was at 16v put a new battery in and it was back to 24v…

The fact that you were able to run the battery down so low that the boost converter started to dropout means that the Power Distribution is doing EXACTLY what was intended - ie successfully power the cRIO and wireless adapter until the battery starts sagging < 6V. I’d consider your observations to indicate an excellent test of the PD … and it easily passed.

Thanks for the feedback! I’ll bet you’ll be more careful about keeping your batteries topped off from now on :wink:


Well it was slightly just running it around for a long period of time also the curiosity of how low the voltage can get before the CRio will actually start losing power…

thanx everyone! it was the battery, we didn’t realize it but when we thought we were charging the battery there wasn’t any power running to the battery, so when we thought we had a full charge, we actually had less than 25%, thanx a ton! we were really worried! haha

I would also just like to mention even though you have solved the problem too for others. that if you are using the Jaguars, they have the fans built in unlike the victors and that the fans only turn on when needed, so there can be on and off somewhat buzzing/humming sound.