Labists Rpi4 fan

I have a Labists case+fan for my Raspberry Pi 4. Usually it runs silently at temperatures below 50 degrees. However this morning, when I switched on there was a brief graunching noise from the case (a moth caught in the fan maybe?) and every three seconds the fan comes on for about one second. The temperature displayed on the Raspberry Pi OS iconbar varies between 45 and 48 degrees. Can anybody diagnose what has happened?

I’d be inclined to examine the fan…

The cheap fans, especially smaller 30mm ones, do tend to have a limited lifespan before they either start making a whining noise or stop working altogether. I have one Labists case which is noisy even after I removed some of the grills obstructing the airflow.

I went through about 4 fanshim fans before I ditched it, I’ve just swapped out another no name 30mm fan to a pi-fan from Makerfocus which is quieter. I had a 35mm fan on a 3B somewhere which was better than the 30mm one, but the best one I have is a Pi 4B case with a larger 40mm fan from ebay, on 3.3V it provides good cooling and is always silent.

on 3.3V it provides good cooling and is always silent.

This, too. I got a generic case with fan for the 3B+, and I run the fan off the 3.3V supply. ¹ It’s silent, unlike the previous 5V fan ², and it shifts enough air that together with the heatsink the machine doesn’t get too hot. It’s 25°C outside and the core temperature is just 36°C. Granted, my room hasn’t warmed up yet, but still…
I have also stepped back the processor to idle at 400MHz (if it’s only doing background stuff, doesn’t need to do it quickly).

¹ I have not yet gotten around to fitting a reset button. So when I reboot I need to disconnect and reconnect the power. I did this briefly the other day and the machine didn’t reboot, it just crashed a bit more. Turns out the latent rotation in the fan kept the 3.3V going enough that the processor kept on ticking… Now, where have I heard that before? ;)

² Powered directly from USB, so I didn’t have a choice. It was a piece of crap that I had to apply oil spray to every other week in an attempt to keep it from sounding like a pre-diarrhoea stomach.

I have not yet gotten around to fitting a reset button

The PSU with the Labist case comes with an integral power switch, (like several others I have), which is kinder to the USB socket in the board then unplugging it all the time.

That’s why I unplug the other end. ;-)

Micro-USB sockets look ridiculously fragile.

I have not yet gotten around to fitting a reset button

The other end usually lives in the cable jungle.

Micro-USB sockets look ridiculously fragile.

On a phone they tend to get made unusable by pocket lint (which can be removed), but assuming you don’t carry your Pi around in a pocket, the usual failure from repeated use is lifting off the circuit board.

Granted, my room hasn’t warmed up yet, but still…

Two days ago: my room hasn’t warmed up, oh well.

Now: my room hasn’t warmed up, thank <Deity$Name>!

It touched 26°C yesterday. Earlier today it got 27.8°C, and it’s supposed to continue and be even hotter ¹ next week. Oh, and can anybody remember the last time it rained properly and not a ten minute cloudburst?

¹ Might be giving my age away if I said ☀️SCORCHIO!🌡️ ;) ²

² https://www.youtube.com/watch?v=mV9q_KdtQfc

That’s not really warm. In the shed which regularly goes over 40C with even a modest amount of sun, a Pi 3B without active cooling quickly hits 80C, but with 30mm fan on 3.3V it stays under 60C. That system has a camera and all Pi’s run hotter the more light camera receives.

Conservatory once recorded 72C here. In early April.

A customer back in the 90s once complained that their Data General system kept crashing and took hours to peform the database integrity checks on restarting before it could be used. Think it was logging drive errors, so I went over with replacement SCSI disk. They’d moved the server into a different equipment room that was close to 50C! It did have air-con running full tilt, but the exhaust vent was split and filling the room with hot air… So they’d opened the windows a bit.

In the shed which regularly goes over 40C with even a modest amount of sun

Last summer I taped an ESP32-CAM to the living room window. Unfortunately the ESP32 cup is hidden inside a metal tin, so no chance of a heatsink. Needless to say, it broke itself.

Symptom? Gibberish from the camera. The camera module works fine on the other board, and using the second camera module also returns gibberish. So some part of the ESP32 has failed.

Next time I try that ¹, I’ll stick a bloody great fan on the back. Might fall off the window through. ;)

¹ Don’t hold your breath, the eternity it takes to bake basic firmware annoys me.

That’s not really warm. In the shed which regularly goes over 40C with even a modest amount of sun

Shed, thin walls(inches?) transmitting heat immediately. As opposed to walls with thickness somewhat greater and transmitting heat, eventually

Now: my room hasn’t warmed up, thank <Deity$Name>!

Meanwhile on the other side of the world, today is the first day that’s actually started to feel like winter. At least, it did earlier. Now that it’s around lunchtime it’s warmed up a bit :)