Help with the ARGON fan hat

This one:

I have it on a Pie… Sitting there turning on/off as needed keeping cool.

I had about 19 weeks uptime clocked on it.

Got home, the Pi was dead.

Reading the docs for the device, pressing the button for about 5 seconds will reboot it - if it has been shutdown via this device.

Leaned in, pressed the button for about 5 seconds.
The fan spun up so all good.
(It’s headless BTW)

Waited, waited and WAITED for it to be back online.

Pressed the button again for 5 seconds and waited for it to shut down.
Pulled the plug, plugged it back in and it whirred back to life.

Shortly after it had booted.


Something’s going on.

Now, let’s work out what happened - yes?

I hear this can shut the pie down if it overheats - which MAY have happened.
I DON’T KNOW :frowning:
(Sorry, I JUST don’t know.)

I have a program that checks the health of the pi - voltage, throttle, temperature, etc.
Anything from them and it is logged.

Nothing in the logs.


Ok, I found a bug in my bit of code that if it detects overheating and it persists for … a while, it shuts down the pi.
But the shutdown command was too quick and that it had been shutdown for that reason would be lots.

But that is if MY code detects an overheat.
(Luckily the condition is broadcast and other machines would know. They too didn’t get any such message.)

So I’m stuck to what EXACTLY happened.

Alas it has now been up for 21 hours.
Any logs would be long gone.

Any suggestions to understanding better how this device shuts down the machine if it overheats?
If it uses the same (or even different) command I use.
Both commands would (you would expect) they BOTH say it is overheating with the same thresholds.
And so although it (the hat detected the overheating - why didn’t my bit of code also?)
(semi rhetorical)


Hi @Andrew41918

What gives you the impression that the Pi shutdown due to an overheat? Is it doing any particularly heavy-lifting? What kind of work is it doing?

Could it be that the button was just bumped to cause a shutdown?

I couldn’t find any mention in the guide that the HAT has a thermal-shutdown utility. Is that documented somewhere?

Hey Michael.

The Pi needs cooling.
But a fan on all the time didn’t seem a good idea.

I got this hat to get around that problem.
The bonus was I could reboot/shutdown the machine if needed.
(It is headless.)
When it locks up it is not a good idea to just pull out the power.

A fair while ago it shut down - reasons unknown.
I stupidly forgot about how to use the TURN ON option offered by the button.
Holding it down for > 3 seconds.

I got home and my system was upset and the main machine wasn’t talking to them.
Couldn’t PING it, couldn’t SSH to it.

Before unplugging the power I remembered if I hold the button down for > 3 seconds, it will turn on again.

You may need to help me with exactly what happens and all the finer details.
What is Soft shutdown?

Anyway, I pressed it, the fan came on and it was working again.

I waited, waited and WAITED… Still couldn’t see it. Ping, SSH, all dead. :frowning:
Now, forgetting if I double press the button it forces a reboot, I unplugged the power and it was soon back up and working.

So somehow it was in that state.

The button couldn’t have been bumped as no one was at home.

So I am trying to work out what is going on.

Another backstory:
Even further back I had one of these hats - on this machine - and one day the fan stalled and wouldn’t run.

As I was out, the Pi overheated. Or more so: went into thermal limiting mode.

This was kind of good as it showed me a problem in the program I wrote to also monitor the health of the machine.

That part fixed and a new hat sent to me I put the new one on.

All should be good.

This is the first time I know of where the fan hasn’t turned on when commanded.

I’m wanting to try and work out what happened.

Alas being a HEADLESS machine it isn’t quite as easy as turning on the monitor.
And it is not possible to connect one to it where it is.


The most likely reason for that is a failure in the software that caused the connection to be lost. Is your monitoring reporting the state of the connection? You have stated that the system was upset, but what did you do to confirm the actual state of the machine? Based on the description of how it shut down and restarted I would suspect that it was simply hung up on some software loop, or perhaps it was trying to report an error. Without knowing the actual setup it’s just a guess. But diagnosis is usually most effective when you start from the most likely scenario and only move onto the more complicated explanations when you have ruled out the simplest ones.

1 Like

Hey Andrew,

Looks like you have a bit of troubleshooting to do here to get to the bottom of this.

A soft shutdown refers to shutting down the OS before powering off the hardware. For comparison a hard shutdown would be shutting off the power at the wall when the Pi is running which is normally not recommended.

In this case your HAT is triggering a soft shutdown through the GPIO pins.

I second what Jeff has said. Moving back through the likely cause and checking your software for any issues would probably be the best way forward.

Yes, I agree. (I have a LOT of trouble shooting to do)

So saying the hat triggered a soft shutdown…


What kinds of things can happen that cause the hat to do a soft shutdown?

Overheating is one - I’m guessing.
But are there any others?

And I shall say I did goof.

I should have quickly pressed the button, not LONG pressed it.

Hi Andrew,

If you remove the fan HAT what does the Pi do? Is there any pattern to the Pi’s ACT LED?

That is not easy.
There is a RTC piggybacked on that and that machine is THE machine.

It has only happened… 3 times.
2 with this hat.

And MONTHS apart.

The ACT LED… That’s the RED one - yeah?
It is turned off to reduce power usage. (I know: petty, but… If it is on at night the room is too bright.)

I’m guessing if I removed it the temperature would go up to about… 50 degrees. (Based on another Pi with no fan that is running.)

As is the temperature is this sort of thing.

The ACT LED is the green one. The red LED signifies power. The green one will blink error messages.

Is it possible to get some pictures of your setup?

Oh, ok. Sorry.


The Pi is not really easily seen.
It is headless and is tucked away at the back of a … Hi-fi rack of the 80’s.

Hi Andrew,

If you are able to access the Pi you will get the most out of troubleshooting. The Pi may be blinking its error messages or there may be something noticeable on the board itself.


But going on the MTBF, it may be 19 weeks for it to happen again.

The Pi wouldn’t respond to ping or ssh. So what ever happened, it was in soft shutdown mode.

Next time - hoping there won’t be - I will press the button on the hat quickly and hope the Pi comes back to life.

Unless you mean NOW.

But it has not been running up 5 days, 15 hours, 15 minutes at time of posting.

Hi Andrew,

We’re not currently sure if the Pi still works, if you can remove it from the rack we can better assess it.

I very much agree with the hopefully there won’t be a next time sentiment but you would be doing yourself a favour by working towards a solution in this instance.

Who is this we?

The Pi IS working.

It WAS working. I went out. I came home and for REASONS UNKNOWN it was shutdown.

But it responded to my mistakenly pressing the button for 4 seconds rather than quickly.
I don’t know what that did, but it was still not talking to me.

I unplugged the power, plugged the power back in and IT IS WORKING
And has been quite happily for 5 days 15 hours 15 minutes at time of my previous post.
Before that it was working for more than 19 weeks.

My suspicion is the hat shut it down.

I am wanting to know ALL the reasons the hat could put the Pi into standby mode.
SOFT SHUTDOWN MODE is the term used.


But it has not been running up 5 days, 15 hours, 15 minutes at time of posting.
Should have been:
Post 8 is/was an ACTIVE screen shot of the pi running AFTER it had been rebooted (power cycled) from the stuck/hung condition.

Hey Andrew,

unfortunately with these Raspberry Pi’s there is any number of reasons that this shutdown may have occurred. The most common causes are normally power supply / draw issues or overheating. Having said that the Pi can and will shut itself down if it thinks this is the best course of action to protect it self.

I am unaware of a full list of the conditions that can trigger this but as a general guide these are the most common reasons for an unexpected shutdown.

I would look out for Insufficient Power, Overheating, Corrupted SD Card, High Processor Usage, Software Bugs, Inappropriate Configuration of the Pi’s settings or Hardware Issues in that order.

Hope this helps!

Hi Andrew

Wouldn’t that be some sort of a record for RPi ??? Seems like a large percentage of the problems on this Forum anyway are RPi based.

I doubt the people who designed it would be able to answer that.

Welcome to the world of intermittent problems. Although 19 weeks is intermittent on steroids. Nobody publishes MTBF numbers these days especially for development / hobby type bits which I think is the category for RPi. So I think at 19 weeks you are probably not doing too bad.
Cheers Bob

I shall take a step back and explain the situation as I see it.

I have THREE machines that are on 24/7.

One has been up 32 weeks +
Second one 14 weeks 4 days
This one now 1 week 2 days.

The second one and this one have this hat on.

When I first bought the hats the one on this machine kept stalling (ie: was stopped and wouldn’t start on command)

I swapped hats and the problem followed the hat.

The hat was replaced and I thought all would be good.

As originally stated:

I was out, came home and this machine had shut down.
With the knowledge of when it happened a few months ago, I didn’t just pull the power and plug it back in.
I remembered the button on the hat.
Alas - to my shame - I did a LONG PRESS, rather than a SHORT PRESS.

Suffice to say it didn’t power it back up.


The machine came back to life - as in: The fan started.

Now, I’m not sure if the machine has been shut down with sudo shutdown if that would happen or not.
NO ONE IS PREPARED TO TELL ME - and alas looking at the hat’s home page: SFA information there also.

So a HUGE UNANSWERED question for me is: “Was the machine in software shutdown mode or was it/had it shut down for other reasons?”

We’ll never know.

But I would like to ask for HELP on how the hat works from anyone who has more knowledge than me.

Power supply, SD card failure… Yeah, right.
Been there, know the problems from those things.
And believe me, for MONTHS - now a long time ago - there are symptoms.
They have been addressed.

Faulty SD card. So why did it reboot and is working now?

Hi Andrew
That is frustration in capital letters.

Maybe no one knows. The way I see it is that the favourite way to fix problems with RPi is to keep changing operating system, flash cards, software and anything else until you get a combination that works. Then when you upgrade your Pi start all over again. Backward compatibility does not seem too good. But if someone does happen to have any clues they should share.

I am not really surprised there. Too much of that going on.

Why for me RPi is on the to do list if and when I need it. Provided of course it has grown up and settled down.
Cheers Bob

I don’t have any suggestions for finding out what happened to your Pi, but I have a suggestion for the future - print out a small list of button functions, glue it onto a piece of cardboard, and attach it to or near the Pi, so you aren’t having to remember rarely-used button sequences in the moment.

There are likely log files on the Pi. Yet these may not tell you what happened and could be an effort to crawl through.

The fan hat only has a few functions so I agree with @Politas that keeping a note with each of the functions nearby will help with issues there.