PCB Microsurgery Puts The Bodges Inside The Board

December 14, 2021 by Dan Maloney 23 Comments

We all make mistakes, and there’s no shame in having to bodge a printed circuit board to fix a mistake. Most of us are content with cutting a trace or two with an Xacto or adding a bit of jumper wire to make the circuit work. Very few of us, however, will decide to literally do our bodges inside the PCB itself.

The story is that [Andrew Zonenberg] was asked to pitch in debugging some incredibly small PCBs for a prototype dev board that plugs directly into a USB jack. The six-layer boards are very dense, with a forest of blind vias. The Twitter thread details the debugging process, which ended up finding a blind via on layer two shorted to a power rail, and another via shorted to ground. It also has some beautiful shots of [Andrew]’s “mechanical tomography” method of visualizing layers by slowly grinding down the surface of the board.

[Andrew] has only tackled one of the bodges at the time of writing, but it has to be seen to be believed. It started with milling away the PCB to get access to the blind via using a ridiculously small end mill. The cavity [Andrew] milled ended up being only about 480 μm by 600 μm and only went partially through a 0.8-mm thick board, but it was enough to resolve the internal short and add an internal bodge to fix a trace that was damaged during milling. The cavity was then filled up with epoxy resin to stabilize the repair.

This kind of debugging and repair skill just boggles the mind. It reminds us a bit of these internal chip-soldering repairs, but taken to another level entirely. We can’t wait to see what the second repair looks like, and whether the prototype for this dev board can be salvaged.

Thanks to [esclear] for the heads up on this one.

What Really Goes Wrong With Your Tablet

December 14, 2021 by Jenny List 33 Comments

We’ve all seen our share of consumer electronic devices that need repair. It’s inevitable that, however well-cared-for it will be, there’s always the unforseen that brings its life to an end. Many of us will be using devices we’ve repaired ourselves, because often other people’s useless broken electronics can be our free stuff when we know how to fix them and they don’t. This is the arena the Restart Project operate in, as through their Restart Parties they provide repair services to save unnecessary landfill. Over nearly a decade in operation they’ve fixed a huge number of faulty items, and now they’re releasing some data and have analysed common fault modes and barriers to repair for some categories.

We’re restricted to tablets, printers, and batteries, and while many of the problems are the wear-and-tear such as tablet screens, power supplies, charging connectors, and paper feeds that most of us would expect, it’s the barriers to repair which the Restart Project are keen to draw attention to. Products that are near-impossible to open without damage, parts such as batteries which are difficult to remove, and unavailability of spares. It’s to become part of their campaigning for legal repairability standards across Europe.

Aside from their own analysis, the full data is all available for download should you have any extra insights. We’ve made our position on this matter very clear indeed.

Fail Of The Week: Hackaday Writer Attempts XBox Repair

December 8, 2021 by Dan Maloney 55 Comments

Like a lot of Hackaday readers, I pride myself on being “the fix-it guy” in my family. When something breaks, I get excited, because it’s a chance to show off my skills. It’s especially fun when something major breaks, like the fridge or the washing machine — repairs like that are a race against time, since I’ve got to get it fixed faster than it would take to hire someone to do it. I usually win the race; I can’t remember the last time I paid someone to work on something. Like I said, it’s a point of pride.

And so when my son came home on Thanksgiving break from his first semester away at college, eager to fire up his Xbox for some mindless relaxation from his biochemistry studies, only to be greeted with a black screen and no boot-up, it was go-time for me. I was confident that I’d be able to revive the dead box in time for him to have some fun. The fact that he’s back at school and the machine is still torn apart on my bench testifies to my hubris, but to be fair, I did get close to a fix, and may still yet get it done. But either way, the lessons I’ve learned along the way have been really valuable and worth sharing.

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Curious Marc Takes On Sewing Machine Repair

November 4, 2021 by Adam Fabio 29 Comments

Even the most talented engineers can be stymied by simple repair projects. In this case, repairing a broken sewing machine has [CuriousMarc] all tangled up. [Marc] is probably best known as a part of the team who managed to restore and boot up an apollo guidance computer, but he’s worked with plenty of other vintage machines.

This problem hit much closer to home. [Marc’s] daughter wanted to sew a Halloween costume. The machine would boot up fine, but when attempting to sew, it would make a bit of noise, then beep and display “The safety device has been activated”. Not very helpful.

The sewing machine in question is called “Baby Lock Decorator’s Choice” and is manufactured by Brother for Juken. [Marc] of course dug in, and quickly found himself stymied by a clamshell case that just didn’t want to come apart. This is the point where many of us would apply just a little too much force when prying and be rewarded with a broken case.

[CuriuosMarc] is thankfully the more patient sort. Rather than become [FuriousMarc], he carefully persevered to find a hidden screw holding things together. The screw could only be accessed by inserting a screwdriver through a tiny access hole on the front chassis of the machine.
With the screw out, a couple of molded clips were all that held the case sides together. After popping them, [Marc] was finally able to fix the real problem: A toothed belt that had slipped off its cog. That’s it — just a loose belt. The cryptic error code most likely was due to the machine realizing it the motor was on, but the machine wasn’t moving – which would generally indicate something stuck or tangled in the thread path.

This type of repair would be much easier if service manuals were readily available. We did a quick search for this model but didn’t find anything freely available.

Have you gotten stuck by a simple repair? Tell us about it down in the comments.

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There’s Not A Cassingle Thing Missing From This Cassette Deck Masterclass

October 26, 2021 by Kristina Panos 78 Comments

For [ke4mcl], this whole cassette craze of late is not a new discovery so much as it is a personal nostalgia machine. Since [ke4mcl] sees a lot of basic questions go unanswered, they made an incredible beginner’s guide to all things cassette deck. This concise wealth of information covers everything from terminology to operation, basic maintenance like repairing the belt and lubricating the motor, and appropriate cleaning methods for the various parts. Yep, we’re pretty sure this covers everything but the pencil winding technique, which you probably already knew about.

You don’t need a lot of tools and supplies to maintain a cassette deck or twelve (apparently they’re addictive) — mostly just head cleaning fluid, isopropyl, window cleaner, and a bunch of cotton swabs. And given this guide, you’ll enter the enclosure confidently, armed with knowledge about everything from the belts to the capstan to the head. This is valuable information, the kind of stuff your older brother wouldn’t take the time to explain to you in the 80s. But maybe he didn’t know reverse bias from the holes in the top of the tape.

Don’t care for the quality of audio cassettes? Tapes are good for lots of stuff, like data storage and decoration.

Valve Reluctantly Shows How To Mod The Steam Deck

October 14, 2021 by Tom Nardi 35 Comments

As the narrator in this official instructional video from Valve reminds the viewer several times, the gaming company would really rather you not open up your brand new Steam Deck and start poking around. They can’t guarantee that their software will function should you start changing the hardware, and since there’s no source for replacement parts yet anyway, there’s not much you can do in the way of repairs.

That said, Valve does believe you have the right to take apart your own device, and has produced the video below as an aid to those who are willing risk damaging their new system by opening it up. Specifically, the video goes over how to replace the most likely wear items on the handheld, namely the thumb sticks and the SSD. It seems inevitable that the stock thumb sticks will wear down after a couple years of hard use, so we’re glad to see they are easily removable modules. As for the SSD, it stands to reason that users would want to swap it out for faster and higher capacity models as they become available in the coming years.

Sooner or later, these are going to need to be replaced.

Now to be clear, we appreciate Valve making this video, and would love to see other manufacturers be so forthcoming. But we have to admit that some of its messaging does seem a bit heavy handed. The narrators admonition that users who open their Steam Deck are literally taking their lives into their own hands due to the danger of potentially rupturing the system’s lithium-ion battery is a bit hyperbolic for our tastes. The constant reminders of how badly you could bungle the job just comes off as overly preachy, though to be fair, we probably aren’t the intended audience.

Outside of its obvious gaming functions, we’re excited too see what the community can do with the Steam Deck. With official reference material like this, perhaps we’ll even start seeing some hardware modifications before too long. Though we wouldn’t blame you for hitting the Mute button halfway through.

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Decoding SMD Part Markings

October 6, 2021 by Chris Lott 29 Comments

You’ve probably encountered this before — you have a circuit board that is poorly documented, and want to know the part number of a tiny SMD chip. Retro computer enthusiast [JohnK] recently tweeted about one such database that he recently found, entitled The Ultimate SMD Marking Codes Database. This data base is only a couple of years old judging from the Wayback Machine, but seems to be fairly exhaustive and can be found referenced in quite a few electronics forums.

Unlike their larger SMD siblings, these chips in question are so small that there is no room to print the entire part number on the device. Instead, the standard practice is for manufacturers use an abbreviated code of just a few characters. These codes are only unique to each part or package, and aren’t necessarily unique across an entire product line. And just because it is standard practice does not imply the marking codes themselves follow any standard whatsoever. This seemingly hodgepodge system works just fine for the development, procurement and manufacturing phases of a product’s lifecycle. It’s during the repair, refurbishment, or just hacking for fun phases where these codes can leave you scratching your head.

Several sites like the one [JohnK] found have been around for years, and adding yet another database to your toolbox is a good thing. But none of them will ever be exhaustive. There’s a good reason for that — maintaining such a database would be a herculean task. Just finding the part marking information for a known chip can be difficult. Some manufacturers put it clearly in the data sheet, and some refer you to other documentation which may or may not be readily available. And some manufacturers ask you to contact them for this information — presumably because it is dynamic changes from time to time. Continue reading “Decoding SMD Part Markings” →