Repairing 200+ Raspberry Pis For A Good Cause

If somebody told you they recently purchased over 200 Raspberry Pis, you might think they were working on some kind of large-scale clustering project. But in this case, [James Dawson] purchased the collection of broken single-board computers with the intention of repairing them so they could be sent to developing countries for use in schools. It sounds like the logistics of that are proving to be a bit tricky, but we’re happy to report he’s at least made good progress on getting the Pis back up and running.

He secured this trove of what he believes to be customer returned Raspberries or the princely sum of £61 ($83 USD). At that price, even if only a fraction ended up being repairable, you’d still come out ahead. Granted all of these appear to be the original Model B, but that’s still a phenomenal deal in our book. Assuming of course you can find some reasonable way to triage them to sort out what’s worth keeping.

To that end, [James] came up with a Bash script that allowed him to check several hardware components including the USB, Ethernet, I2C, and GPIO. With the script on an SD card and a 3.5″ TFT plugged into the Pi’s header for output, he was able to quickly go through the box to get an idea of what sort of trouble he’d gotten himself into. He was only about half way through the process when he wrote his blog post, but by that point, had only found 40 Pis which wouldn’t start at all. He suspects these might be victims of some common issue in the power circuitry that he’ll investigate at a later date.

The majority of Pis he checked were suffering from nothing worse than some bent GPIO pins or broken SD card slots. Some of the more abused examples had their USB ports ripped off entirely, but were otherwise fine. Another 10 had dead Ethernet, and 4 appear to have damaged traces leading to their HDMI ports. While we’re interested in hearing if [James] can get those 40 dark Pis to fire back up, so far the results are quite promising.

Donating hardware is always a tricky thing, so for now [James] says he’ll be selling the repaired Pis on eBay and donating the proceeds to the Raspberry Pi Foundation so they can continue to develop hardware that will (potentially) accomplish their goal of giving students all over the world a functional computer.

Burned Out SKR E3 Mini Gets New Stepper Driver

It didn’t take long to figure out that a dead X axis and an message saying “TMC CONNECTION ERROR” meant that one of the stepper drivers on the SKR E3 Mini 3D printer control board had released the magic smoke. Manufacturer BigTreeTech replaced the board under warranty, and the printer was back up and running in short order. But instead of tossing it in the trash, [Simon] wondered how hard it would be to repair the dead board.

Removing the original stepper driver IC.

The short answer is, not very hard. There was no question as to which of the four TMC2209 drivers was shot, since the X motor was the only one experiencing a problem. The drivers unfortunately aren’t socketed on this board, but after a little kiss with the hot air, the old chip was off.

[Simon] didn’t have any spare TMC2209 chips, but the TMC2208 has the same pinout and is a drop-in replacement. The TMC2208 is rated for a bit less current, but it shouldn’t be a problem under normal circumstances.

Other than the stepper connector getting a little toasty during the installation, the swap went off without a hitch and the board was up and running again. [Simon] ended up putting the now repaired SKR E3 Mini in his Ender 3; a nice 32-bit upgrade compared to the ATmega1284 that was originally running the show. Though in the past, he’s managed to squeeze a bit more performance out of the older 8-bit board as well.

Uncommon Bárány Chair Gets Fixed Up

Ever heard of a Bárány chair? Neither had [Troy Denton] before he was asked to repair one, but that didn’t stop him from rolling up his sleeves and tying to get the non-functional device back in working order. As it didn’t come with a user guide, manual, schematic or any other information, he had to rely on his experience and acumen gathered over years of practical work. Luckily for us, he decided to document the whole process.

While it’s not well known outside of aviation circles, the Bárány chair is an important piece of equipment in training pilots to get used to spatial disorientation. The device is essentially a motorized revolving chair, the idea being to spin the subject to induce disorientation. Rotation speed and direction can be controlled via a handheld wireless remote terminal.

When [Troy] first powered it up, the error code on the remote indicated “no power to base unit”. That turned out to be a quick fix – he simply had to move the power connection from a switched socket that had been turned off to a different outlet. But while that cleared the error message, the chair still wouldn’t rotate for any of the knob settings.

Manually rotating the chair showed the RPM on the remote, so [Troy] narrowed down his search to the motor related sections. The motor was being driven by a servo type signal, but changing the speed and direction knob on the remote didn’t seem to alter the control signal when he checked it with his scope. Opening up the hand held remote immediately uncovered the failed part – the rotary encoder for setting the speed and direction had physically split in to two pieces.

Since there was a clean split in the encoder, he was able to temporarily hold it back together to confirm that the chair could spin up. The cause was most likely “User Error” – the last person to conduct the test probably turned the knob rather enthusiastically. A new part is on the way, and the chair should be getting back to making prospective pilots dizzy in no time.

We love a good repair story here at Hackaday. Whether it’s patiently rebuilding a snapped PCB with bodge wires or coming up with replacement parts that may well be better than the originals, we never get tired of seeing a broken piece of gear put back together.

Continue reading “Uncommon Bárány Chair Gets Fixed Up”

Think Your Laptop Is Anemic? Try An MSDOS One

If someone gifted you a cheap laptop this holiday season, you might be a little put out by the 2GB of RAM and the 400 MHz CPU. However, you might appreciate it more once you look at [Noel’s Retro Lab’s] 4.8 Kg Amstrad PPC512 He shows it off inside and out in the video below.

Unlike a modern laptop, this oldie but goodie has a full keyboard that swings out of the main body. The space below the keyboard contains the LCD screen, which [Noel] is going to have to replace with an LCD from another unit that was in worse shape but had a good-looking screen. In this video, he gets as far as getting video output to an external monitor, but neither LCD shows any sign of life. But he’s planning more videos soon.

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European Right To Repair: Poor Repairability Shamed With Rating System

Happily the right to repair movement is slowly gaining ground, and recently they’ve scored a major success in the European Parliament that includes a requirement that products be labelled with expected lifetime and repairability information, long-term availability of parts, and numerous measures aimed at preventing waste.

… including by requiring improved product information through mandatory labelling on the durability and reparability of a product (expected lifetime, availability of spare parts, etc.), defining durability and reparability as the main characteristics of a product…

Even the UK, whose path is diverging from the EU due to Brexit, appears to have a moment of harmony on this front. This builds upon existing rights to repair in that devices sold in Europe will eventually have to carry a clearly visible repair score to communicate the ease of repairability and supply of spare parts, making a clear incentive for manufacturers to strive for the highest score possible.

We live in an age in which our machines, appliances, and devices are becoming ever more complex, while at the same time ever more difficult to repair. Our community are the masters of fixing things, but even we are becoming increasingly stumped in the face of the latest flashy kitchen appliance or iDevice. The right to repair movement, and this measure in particular, seeks to improve the ability of all consumers, not just us hackers, to makebuying decisions for better products and lower environmental impact.

With a population of around 450 million people spread across 27 member countries, the EU represents a colossal market that no manufacturer can afford to ignore. Therefore while plenty of other regions of the planet have no such legislation this move will have a knock-on effect across the whole planet. Since the same products are routinely sold worldwide it is to be expected that an improvement in repairability for European markets will propagate also to the rest of the world. So when your next phone has a replaceable battery and easier spares availability, thank the EU-based right to repair campaigners and some European lawmakers for that convenience.

European Parliament from EU, CC BY 2.0.

Trashed Tablet Lives Again Thanks To New Charger IC

Have you ever pulled a piece of electronics from the trash that looked like nothing was wrong with it, only to take it home and find out it really is dead? Since you’re reading Hackaday, we already know the answer. Trash picking is an honored hacker tradition, and we all know it’s a gamble every time you pull something from the curb. But when the Samsung Galaxy Tab S that [Everett] pulled from the e-waste bin wouldn’t take a charge, he decided to crack it open and see if it was really beyond repair.

The first step was using a USB power meter to see if the tablet was actually pulling any current when plugged in. With just 10 mA on the line, [Everett] knew the device wasn’t even attempting to charge itself. So his next step was to pull the battery and charge it from a bench supply. This got the tablet to wake up, and as far as he could tell, everything else worked as expected. It seemed like the only issue was a blown charging circuit.

Where we’re going, we don’t need ribbon cables.

Now at this point, [Everett] could have just gone online and bought a new motherboard for the tablet and called it a day. But where’s the fun in that? Instead, he wired up a simple charging circuit using a TP4056 IC on a scrap of flexible PCB and mounted it to a square of Kapton tape. He then used 34 AWG magnet wire to connect it between the tablet’s USB port and the battery, bypassing the tablet’s electronics entirely.

The fix worked, but there was a slight problem. Since the TP4056 only goes up to 4.2 V and the battery maxes out at 4.35 V, [Everett] says his hacked charger can only bring the tablet up to 92% capacity according to Android. But considering the alternative, we think its more than a worthy trade-off.

It’s easy to dismiss tablets as largely disposable devices, but this isn’t the first time we’ve seen somebody save one with little more than solder and patience. Of course, what you do with that old tablet once you get it fired back up is another story entirely.

A Microwave Repair Even Mechanical Keyboard Fans Will Love

Microwave oven design and manufacturing have been optimized to the point where the once-expensive appliances are now nearly disposable. Despite the economics, though, some people can’t resist fixing stuff, especially when you get a chance to do it in style. Thus we present this microwave repair with its wholly unnecessary yet fabulous adornments.

The beginning of the end for [dekuNukem]’s dirt cheap second-hand microwave started where many of the appliances begin to fail first — the membrane keyboard. Unable to press the buttons reliably anymore, [dekuNukem] worked out the original keypad’s matrix wiring arrangement and whipped up a little keypad from some pushbutton switches and a scrap of perfboard. Wired into the main PCB, it was an effective and cheap solution, if a bit on the artless side.

To perk things up a bit, [dekuNukem] turned to duckyPad, a hot-swappable macropad with mechanical switches and, of course, RGB LEDs. Things got interesting from here; since duckyPad outputs serial data, an adapater was needed inside the microwave. An STM32 microcontroller and a pair of ADG714 analog switches did the trick, with power pulled from the original PCB.

The finished repair is pretty flashy, and [dekuNukem] now has the only microwave in the world with a clicky keypad. And what’s more, it works.

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