The Ultimate Raspberry Pi Stress Test -- Episode 400

Relay interesting video - I enjoy seeing equipment being pushed to its limits. I've spent a bunch of my career in testing and qualifying electronics for use in electrical substation environments, and I've made more than one manufacturer cry by the end of testing

Some tests that I think are relatively easy to be done in the home shop...

• Power up from cold soak. It's one thing to cool down a piece of electronic kit that's already running; it's a totally different thing to power the unit down, let it drop to a low temperature, and then turn it on. There are all sorts of problems that can arise with the sequencing of various power rails that can really cause havoc with a cold-start power up. Put the RPi into the liquid nitrogen bath with the power off, let it sit for a bit to let it reach steady state temperature (or as cold as you're willing to try), and then turn the power on.
• High altitude simulation: Put the RPi in a vacuum chamber and drop the ambient pressure as low as it will go.
• High magnetic field: Big, tight coil of wire with lots of turns per meter, with a RPi in the centre, rotated through different orthogonal orientations. Try low frequency (50-60 Hz - easy with a wall supply) and if possible, higher frequencies (e.g. 400 Hz - typical shipboard/marine applications) although it might be difficult to get a power supply to do 400 Hz. Wait a minute - this is Element14...
• Torsional board loading: Rather than a "uniform" pressure across the board, try different bending/twisting loads. Cantilever the board over the edge of a table and try hanging progressively heavier weights either from both corners or a single corner. Looking for solder cracking or PCB trace delamination.
• Shake...: See if you can bodge together a simple vibration table (Orbital sander, sawzall, or ideally a couple of pieces of heavy plate steel, some heavy duty springs, and a reciprocating motor). Bolt the RPi to it (again, different orthogonal mounting orientations) and see what shakes loose.
• ...And Bake: Get a toaster oven, set the temperature to 150-200C, put a couple of RPis in and see how long they will run until failure - long reliability is important too, and this gives at least some gauge as to how long a RPi would last under more typical environmental conditions (we typically require a hot soak of 16 hours at 85C as part of a Highly Accelerated Stress Screen (HASS) protocol for equipment prior to shipping to weed out any infant mortality).

Also,  I think the increased temperature in your radiation test is just the combination of poor coefficient of heat transfer between the CPU and GPU cases and the paper towel (instead of air), and the loss of pretty much all convective cooling of the components from the restricted airflow. If you didn't have any of the tests failing (particularly the memory test) it's unlikely that radiation had anything to do with the temperature rise. Simple way to prove this would be to use a block of pretty much anything else (non-radioactive) in lieu of the ADF with the same paper towel and see the result.

Thanks! I know that there's a ton of other tests I could do to this (or, really, any) board, so perhaps a follow-up is in order?

I think you're probably right about the temperature rise during the radiation test. If I try it again, I'll likely build a small rig to suspend the source above the board and run more memory-intensive tests for that particular battery. I expected some temperature difference with the paper towel in place, but I hadn't anticipated that much, which is probably the reason for my surprise more than the (lack of) effect of radiation bombardment. Hooray peer review!

My shopmate just built a Lego sorter based on a reciprocating motor, so it might be a good opportunity to perform those shake tests.

Stay tuned....

Thanks! I know that there's a ton of other tests I could do to this (or, really, any) board, so perhaps a follow-up is in order?

I think you're probably right about the temperature rise during the radiation test. If I try it again, I'll likely build a small rig to suspend the source above the board and run more memory-intensive tests for that particular battery. I expected some temperature difference with the paper towel in place, but I hadn't anticipated that much, which is probably the reason for my surprise more than the (lack of) effect of radiation bombardment. Hooray peer review!

My shopmate just built a Lego sorter based on a reciprocating motor, so it might be a good opportunity to perform those shake tests.

Stay tuned....

Hello:

Nice project, but ...

Just *where* is the link to the test script?

Cannot seem to find it, not in the description (?).

Thanks in advance.

Best,

L14

While it isn't available as a downloadable script, you can recreate it from the 1080p video footage https://youtu.be/1bgkInAIG7Y?t=112