Repairing An HP Power Supply

December 15, 2023 by Al Williams 3 Comments

One of the interesting things about living in modern times is that a confluence of the Internet and rapid changes in the electronics industry means that test gear that used to be astronomically priced is now super affordable. Especially if, like [Frankie Mashockie], you can do a little repair work. He picked up an HP6038A power supply for $50. We couldn’t find the original list price, but even refurbs from “professional” sources go for around $800. However, the $50 price came with a “for parts” disclaimer.

The power supply is autoranging. You usually think of that as a feature of meters. In a power supply, autoranging means the device can adjust the voltage based on load as you can see explained in the video below.

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Hacker Tactic: Internal ESD Diode Probing

December 14, 2023 by Arya Voronova 15 Comments

Humans are walking high voltage generators, due to all the friction with our surroundings, wide variety of synthetic clothes, and the overall ever-present static charges. Our electronics are sensitive to electrostatic discharge (ESD), and often they’re sensitive in a way most infuriating – causing spurious errors and lockups. Is there a wacky error in your design that will repeat in the next batch, or did you just accidentally zap a GPIO? You wouldn’t know until you meticulously check the design, or maybe it’s possible for you to grab another board.

Thankfully, in modern-day Western climates and with modern tech, you are not likely to encounter ESD-caused problems, but they were way more prominent back in the day. For instance, older hackers will have stories of how FETs were more sensitive, and touching the gate pin mindlessly could kill the FET you’re working with. Now, we’ve fixed this problem, in large part because we have added ESD-protective diodes inside the active components most affected.

These diodes don’t just help against ESD – they’re a general safety measure for protecting IC and transistor pins, and they also might help avoid damaging IC pins if you mix. They also might lead to funny and unexpected results, like parts of your circuit powering when you don’t expect them to! However, there’s an awesome thing that not that many hackers know — they let you debug and repair your circuits in a way you might not have imagined.

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Tech In Plain Sight: Super Glue

December 11, 2023 by Richard Baguley 69 Comments

Many inventions happen not by design but through failure. They don’t happen through the failure directly, but because someone was paying attention and remembered the how and why of the failure, and learns from this. One of these inventions is Super Glue, the adhesive that every tinkerer and engineer has to hand to stick pretty much anything to anything, quickly. Although it was a complete failure for the original uses it was developed for, a chemist with good memory and an eye for a helpful product created it in a process he described as “one day of synchronicity and ten years of hard work.”

Super Glue was initially invented in 1942, when the chemist Harry Coover was working on a team trying to develop a clear plastic gun sight that would be cheaper than the metal ones already in use. The team cast a wide net, trying a range of new materials. Coover was testing a class of chemicals called cyanoacrylates. They had some promise, but they had one problem: they stuck to pretty much everything. Every time that Coover tried to use the material to cast a gun sight, it stuck to the container and was really hard to remove.

When the samples he tried came into contact with water, even water vapor in the air, they immediately formed an incredibly resilient bond with most materials. That made them lousy manufacturing materials, so he put the cyanoacrylates aside when the contract was canceled. His employer B. F. Goodrich, patented the process of making cyanoacrylates in 1947, but didn’t note any particular uses for the materials: they were simply a curiosity.

It wasn’t until 1951 when Coover, now at Eastman Kodak, remembered the sticky properties of cyanoacrylates. He and his colleague Fred Joyner were working on making heat-resistant canopies for the new generation of jet fighters, and they considered using these sticky chemicals as adhesives in the manufacturing process. According to Coover, he told Joyner about the materials and asked him to measure the refractive index to see if they might be suitable for use. He warned him to be careful, as the material would probably stick in the refractometer and damage it. Joyner tested the material and found it wasn’t suitable for a canopy but then went around the lab using it to stick things together. The two realized it could make an excellent adhesive for home and engineering use. Continue reading “Tech In Plain Sight: Super Glue” →

The Latest John Deere Repair Lawsuit Now Has The Go-Ahead

December 8, 2023 by Jenny List 50 Comments

Long time readers will have followed the twists and turns of the John Deere repair saga, in which the agricultural machinery manufacturer has used DRM to restrict the repair of its tractors. It may be hot stuff on the prairies, but it matters to everyone because it’s a key right-to-repair battleground. Now the company’s attempt to throw out the latest class-action lawsuit, this time in Illinois. has failed, paving the way for a meaningful challenge.

This lawsuit is special because has the aim of determining whether or not Deere conspired to drive up the cost of repair and edge out independent mechanics. It comes against a backdrop in which their promised access to repair software which we reported on back in January has failed to materialize, and this is likely to figure as an act of bad faith.

A failing of corporate culture is that the organisation can in its own eyes, never be wrong. In Deere’s case they have accrued plenty of bad publicity in the years they’ve pursued this ill-advised business model, and in case that weren’t enough they’ve alienated their core customers out on the farms to the extent that a second-hand Deere from before the DRM era has more value than its newer counterparts. Deere genuinely do make very good tractors, so for farmers loyal for generations to turn their backs on them is a very significant story indeed. One has to ask, how much bad publicity and how many lawsuits do they have to have before someone at head office in Moline figures out that DRM in tractors (or anything else for that matter) isn’t the great idea they once thought it was? Maybe this one will finally herald the moment when that happens.

Header image: Nheyob / CC BY-SA 4.0

Resurrecting A Bricked Wii U With A Raspberry Pi Pico

November 29, 2023 by Lewin Day 6 Comments

There are reports that some Nintendo Wii U systems out in the wild are falling victim to mysterious failures. As is so often the case, certain error codes have been found in common across failed units out in the community, and [Voultar] decided to investigate to see if he could fix this problem with a little hacking.

[Voultar] wasn’t able to source a Wii U with the much-discussed NAND failure mode, but he was able to source a number of supposedly bricked Wii U systems displaying the error codes 160-0101 and 160-0103. The hack is achieved with an exploit in the Wii U’s USB Host Stack descriptor parsing module, developed by [GaryOderNichts]. It allows the injection of a payload that lets one run unsigned code on the Wii U, achieved via a Raspberry Pi Pico. The Pico is ultimately used to boot off an SD card running a recovery program for the Wii U. By resetting the Wii U’s “coldboot title ID”, it solves the error and gets the console booting properly, as per normal.

[Voultar] was able to fix five consoles displaying the common error messages, which we’d call a win. It’s not going to be a fix for every failed Wii U out there, but if you’ve got the dreaded 160-0101 or -0103 errors, it might be worth a shot.

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LiPo Replacement Keeps Portable Scanner In The Action

November 21, 2023 by Dan Maloney 8 Comments

If there’s anything people hate more than being locked into a printer manufacturer’s replacement cartridges, it’s proprietary batteries. Cordless power tools are the obvious example in this space, but there are other devices that insist on crappy battery packs that are expensive to replace when they eventually die.

One such device is the Uniden Bearcat BC296D portable scanner that [Robert Guildig] found for a song at a thrift store, which he recently gave a custom LiPo battery upgrade. It came equipped with a nickel-cadmium battery pack, which even under the best of circumstances has a very limited battery life. Using regular AA batteries wasn’t an option, but luckily the space vacated by the OEM battery pack left a lot of room for mods. Those include a small module with BMS functions and a DC-DC converter, a 2,400 mAh 4.2 V LiPo pillow pack, and a new barrel connector for charging. With the BMS set for six volts and connected right to the old battery pack socket, the scanner can now run for seven hours on a one-hour charge. As a bonus, the LiPo pack should last a few times longer than the NiCd packs, and be pretty cheap to replace when it finally goes too. There’s a video after the hop with all the details.

If you’re looking at a similar battery replacement project, you might want to check out [Arya]’s guide to everything you need to know about lithium-ion circuitry.

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A Classic Shortwave Radio Restored

November 12, 2023 by Al Williams 20 Comments

Before the Internet, if you wanted to hear news from around the world, you probably bought a shortwave receiver. In the golden age of world band radio, there was a great deal of high-quality programming on the shortwave bands and a large variety of consumer radios with shortwave bands. For example, the Sony CRF-160 that [M Caldeira] is restoring dates from the late 1960s or early 1970s and would have been a cool radio in its day. It retailed for about $250 in 1972, which sounds reasonable, but — don’t forget — in 1972 that would have been a 10% downpayment on a new car or enough to buy a Big Mac every day for a year with change left over.

As you can see in the video below, the radio seemed to work well right out of the gate, but the radio needed some rust removal and other sprucing up. However, it is an excellent teardown, with some tips about general restoration.

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