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Ruined 1993 ThinkPad Tablet Brought Back From The Brink

Por: Lewin Day
18 Noviembre 2024 at 09:00

Collecting retrocomputers is fun, especially when you find fully-functional examples that you can plug in, switch on, and start playing with. Meanwhile, others prefer to find the damaged examples and nurse them back to health. [polymatt] can count himself in that category, as evidenced by his heroic rescue of an 1993 IBM ThinkPad Tablet.

The tablet came to [polymatt] in truly awful condition. Having been dropped at least once, the LCD screen was cracked, the case battered, and all the plastics were very much the worse for wear. Many of us would consider it too far gone, especially considering that replacement parts for such an item are virtually unobtainable. And yet, [polymatt] took on the challenge nonetheless.

Despite its condition, there were some signs of life in the machine. The pen-based touch display seemed to respond to the pen itself, and the backlight sort of worked, too. Still, with the LCD so badly damaged, it had to be replaced. Boggling the mind, [polymatt] was actually able to find a 9.4″ dual-scan monochrome LCD that was close enough to sort-of fit, size-wise. To make it work, though, it needed a completely custom mount to fit with the original case and electromagnetic digitizes sheet. From there, there was plenty more to do—recapping, recabling, fixing the batteries, and repairing the enclosure including a fresh set of nice decals.

The fact is, 1993 IBM ThinkPad Tablets just don’t come along every day. These rare specimens are absolutely worth this sort of heroic restoration effort if you do happen to score one on the retro market. Video after the break.

Repairing The Questionable £25,000 Tom Evans Audiophile Pre-Amp

Por: Maya Posch
15 Noviembre 2024 at 00:00
One of the power supply boards in the Tom Evans Mastergroove SR MkIII preamplifier. (Credit: Mend it Mark, YouTube)
One of the power supply boards in the Tom Evans Mastergroove SR MkIII preamplifier. (Credit: Mend it Mark, YouTube)

It’s not much of a secret that in the world of ‘audiophile gear’ there is a lot of snake oil and deception, including many products that are at best of questionable value. The Tom Evans Mastergroove SR mkIII preamplifier is one example of this, as [Mark] from the Mend it Mark YouTube channel found in a recent video when he got one to repair which the manufacturer claimed ‘could not be fixed’. This marvel of audio engineering provides amplification for record players, for the low-low price of only twenty-five thousand quid, or about 29.000 US bucks. So what’s inside one of these expensive marvels?

Claiming to be a high-end unit, with only ten units produced per year, you’d expect a gold-plated PCB with excellent noise isolation. The unit does come with an absolutely massive external power supply that dwarfs the preamplifier itself, but the real surprise came after opening up the unit itself to take a peek at the damage, some of which was caused by transport.

As it turns out, the inside of the preamplifier consists out of four stacks of rather cheap, home-made looking boards with what looks like improvised RF shielding in the form of bare PCBs and filed-off markings on many parts. In between the rat’s nest of wiring running everywhere, [Mark] had to trace the broken channel’s wiring, creating a full repair manual in the process. Along the way one of the opamp boards was found to be defective, courtesy of a single shorted tantalum capacitor.

With the tantalum capacitor replaced, [Mark] had repaired the unit, but even though the preamplifier isn’t terribly designed, the illusion of its price tag has been shattered worse than the contents of a parcel kicked across the parking lot by the Royal Mail.

Thanks to [Jim] for the tip.

Reviewing the World’s 2nd Smallest Thermal Camera

7 Noviembre 2024 at 09:00

A thermal camera is a very handy tool to have, and [Learn Electronics Repair] wanted to try out the Thermal Master P2 for electronic repair, especially since it claims to have a 15 X digital zoom and 1.5 degree accuracy. The package proudly states the device is the “World 2nd Smallest Thermal Camera” — when only the second best will do.

The camera is tiny and connects to a PC or directly to a tablet or phone via USB C. However, it did look easier to use on the end of a cable for probing things like a PC motherboard. The focus was fairly long, so you couldn’t get extremely close to components with the camera. The zoom somewhat makes up for that, but of course, as you might expect, zooming in doesn’t give you any additional resolution.

He also compares the output with that of a multimeter he uses that includes an IR camera (added to our holiday gift list). That multimeter/camera combo focuses quite closely, which is handy when picking out a specific component. It also has a macro lens, which can zoom up even more.

We’ve looked at — or, more accurately, through — IR cameras in the past. If you are on a tight budget and you have a 3D printer, you might try this method for thermal imaging, but it doesn’t use the printer the way you probably think.

Fix That Old Remote With Graphite

1 Noviembre 2024 at 23:00

A button that stopped working has probably led to more than a few smashed remotes over the years. Fortunately [pescado99] has shared a beautifully simple cure for dead or dying remote buttons: graphite dry lubricant.

Most remotes operate by pushing a conductive carbon coating on the back of the button onto a pair of contacts on the PCB. Unfortunately, that conductive coating can wear off, leaving you with a dead or dying button. The video after the break [pescado99] demonstrates how to use a cotton swab to apply powdered graphite to the rear of the buttons to make them conductive again. A soft pencil can also be used, but the graphite works better.

This beautifully simple hack is too good not to share and could save many remotes from landfills. If you’re more interested in upgrading remote, you can build your own universal remote or replace it with a web browser.

The Nixie Tube Multimeter That Almost Made a Comeback

1 Noviembre 2024 at 18:30
Close up of a DA14 nixie multimeter

In a world of digital monotony, the Avo DA14 digital multimeter, with its vintage J Nixie tube charm, is a refreshing gem. Recently refurbished by [Thomas Scherrer], this multimeter video review is a blend of nostalgia and tech savvy. The DA14 not only has style, but substance — delivering resistance, current, and voltage measurements that make you wonder why more multi-meters didn’t stick with this stylish glow.

As [Thomas] starts by powering up the DA14, we were instantly captivated as the Nixie tubes illuminate in their retro orange. With each twist of the dial, he demonstrates just how intuitive the multimeter is to operate, walking us viewers through each function while giving some extra love to its calibration process—a neat front-panel potentiometer that requires just a touch of finesse to get perfect readings.

But, as with all good tinkering tales, things go downhill when issues with analog inputs and the display pop up. A teardown reveals a beautifully complex inner assembly of transformers, rectifiers, and circuit boards, giving the DA14 its impressive yet fragile structure. When the critical defective display chip is found, hopes for a full repair dim. His story ends without a revival, but if you want to see a similar attempt that did get resurrected – albeit without those nixie digits – take a look at this LCD transplant we covered previously.

Cataract Surgery For An Old TV

Por: Lewin Day
1 Noviembre 2024 at 05:00

TVs used to be round, and the GE M935AWL is a great example of that. [bandersentv] found one of these ancient sets, but found it had a “cataract”—a large ugly discoloration on the tube. He set about repairing the tube and the set, restoring this grand old piece back to working order.

The video begins with the removal of the round CRT tube. Once it’s extracted from the set, it’s placed in a round garbage can which serves as a handy work stand for the unique device. It’s all delicate work as it’s very easy to damage a picture tube, particularly an old one. Removing the discoloration is quite a job—the problem is caused by adhesive holding the front layer safety glass on, which has going bad over the years. It requires lots of heat to remove. In doing this repair, [bandersentv] notes he’s also giving up the safety of the original extra glass layer on the front of the tube. Worth noting if you’re worried about a given tube’s integrity.

Of course, cleaning the tube is just part of the job. [bandersentv] then gave us a second video in which he returns the tube to its original home and gets the TV back up and running. The quality is surprisingly good given what poor shape the tube was in to begin with.

It’s funny, because modern TV repair is altogether a rather different affair.

Lies, Big Lies and LED Lightbulb Lifespan Promises

Por: Maya Posch
29 Octubre 2024 at 23:00
Checking the voltages on a dead LED lightbulb. Best done by a professional, obviously. (Credit: The Doubtful Technician, YouTube)
Checking the voltages on a dead LED lightbulb. Best done by a professional, obviously. (Credit: The Doubtful Technician, YouTube)

We have probably all seen the marketing blurbs on packaging and elsewhere promoting the amazing lifespan of LED lighting solutions. Theoretically you should be able to install a LED bulb in a fixture that used to hold that incandescent lightbulb which had to be replaced annually and have it last a decade or longer. Yet we seem to replace these LED bulbs much more often than that, with them suffering a range of issues. To get to the root cause of this, [The Doubtful Technician] decided to perform an autopsy on a couple of dead lightbulbs which he got from a variety of sources and brands.

One lamp is an Amazon-bought one from a seller who seems to have vanished, but was promised over 3 years of constant use. Other than the fun of blinding of oneself while testing, this one was easy to diagnose, with a dodgy solder joint on a resistor in a MELF package. The next one from Lowes was very dim, and required popping open with some gentle force, which revealed as likely culprit a shorted SMD resistor. Finally a more substantial (i.e. heavier) bulb was tested which had survived about 7 years in the basement until it and its siblings began to suddenly die. Some might consider this the normal lifespan, but what really failed in them?

The electronics in this last bulb were the most impressive, with a full switch mode power supply (SMPS) that appears to have suffered a failure. Ultimately the pattern with these three bulbs was that while the LEDs themselves were still fine, it were things like the soldering joints and singular components on the LED driver PCB that had failed. Without an easy way to repair these issues, and with merely opening the average LED lightbulb being rather destructive, this seems like another area where what should be easy repairs are in fact not, and more e-waste is created.

BNCs For An Old Instrument

Por: Jenny List
27 Octubre 2024 at 20:00

Back in the summer our eye was caught by [Jazzy Jane]’s new signal generator, or perhaps we should say her new-to-her signal generator. It’s an Advance E1 from around 1950, and it was particularly interesting from here because it matches the model on the shelf above this bench. She’s back with a new video on the E1, allowing us a further look inside it as she replaces a dead capacitor, gets its audio oscillator working, and upgrades its sockets.

Treating us to a further peek inside the unit, first up is a leaky capacitor. Then a knotty question for old tech enthusiasts, to upgrade or not? The ancient co-ax connectors are out of place on a modern bench, so does originality matter enough to give it a set of BNC sockets? We’d tend to agree; just because we have some adapters for the unit here doesn’t mean it’s convenient. Following on from that is a period variable frequency audio mod which has failed, so out that comes and a little fault-finding is required to get the wiring of the audio transformer.

These instruments are not by any means compact, but they do have the advantage of being exceptionally well-built and above all cheap. We hope readers appreciate videos like the one below the break, and that you’re encouraged not to be scared of diving in to older items like this one to fix them. Meanwhile the first installment is here.

Apple iOS 18’s New Repair Assistant: Easier Parts Pairing Yet With Many Limitations

Por: Maya Posch
27 Octubre 2024 at 17:00
A stack of Activation Locked MacBooks destined for the shredder in refurbisher [John Bumstead]’s workshop.

Over the years, Apple has gone all-in on parts pairing. Virtually every component in an iPhone and iPad has a unique ID that’s kept in a big database over at Apple, which limits replacement parts to only those which have their pairing with the host system officially sanctified by Apple. With iOS 18 there seems to be somewhat of a change in how difficult getting a pairing approved, in the form of Apple’s new Repair Assistant. According to early responses by [iFixit] and in a video by [Hugh Jeffreys] the experience is ‘promising but flawed’.

As noted in the official Apple support page, the Repair Assistant is limited to the iPhone 15+, iPad Pro (M4) and iPad Air (M2), which still leaves many devices unable to make use of this feature. For the lucky few, however, this theoretically means that you can forego having to contact Apple directly to approve new parts. Instead the assistant will boot into its own environment, perform the pairing and calibration and allow you to go on your merry way with (theoretically) all functionality fully accessible.

The bad news here is that parts whose IDs show up as being locked (Activation Lock) are ineligible, which is something you cannot tell when you’re buying replacement parts. During [iFixit]’s testing involving swapping logic boards between two iPhone 15 Pros they found many issues, ranging from sudden reboots during calibration and boot looping. Some of these issues were due to the captive-portal-based WiFi network at [iFixit] HQ, but after eliminating that variable features like Face ID still refused to calibrate among other issues.

Meanwhile [Hugh]’s experiences have been more positive, but the limited nature of this feature, and the issues surrounding used and third-party parts, mean that the practical use of this Repair Assistant will remain limited, with tons of perfectly fine Activation Locked parts scrapped each year and third-party parts requiring pairing hacks to make basic features work, even on Apple’s MacBooks.

IOS 18 also adds battery monitoring for third-party batteries, which is a nice touch, but one cannot help but get the feeling that Apple is being dragged kicking and screaming into the age of easy repairs and replacements with Apple devices.


Featured image: A stack of Activation Locked MacBooks destined for the shredder in refurbisher [John Bumstead]’s workshop.

McDonalds Ice Cream Machines Gain A DMCA Exemption

Por: Jenny List
26 Octubre 2024 at 20:00
Sad clown holding melted ice cream cone

An unlikely theatre for an act in the right-to-repair saga came last year in the form of McDonalds restaurants, whose McFlurry ice cream machines are prone to breakdown. The manufacturer had locked them down, and a franchisee with a broken machine had no option but to call them for an expensive repair job. iFixit and Public Knowledge challenged this with a request for a DMCA exemption from the Copyright Office, and now news emerges that this has been granted.

The exemption in question isn’t specific to McDonalds, instead it applies to retail food preparation equipment in general, which includes ice-cream machines. We’re guessing that franchisees won’t be breaking out the screwdrivers either, instead it’s likely to lower significantly the cost of a service contract for them and any other food industry operators hit with the same problem. Meanwhile any hackers who’ve picked up an old machine can now fix it themselves without breaking the law, and maybe the chances of your local Mickey D’s having no McFlurries have gone down.

This story has featured more than once on these pages, so catch up here, and here.

Simple PCB Repairs Keep Old Vehicle Out of the Crusher

24 Octubre 2024 at 20:00

For those of us devoted to keeping an older vehicle on the road, the struggle is real. We know that at some point, a part will go bad and we’ll learn that it’s no longer available from the dealer or in the aftermarket, at least at a reasonable cost. We might get lucky and find a replacement at the boneyard, but if not — well, it was nice knowing ya, faithful chariot.

It doesn’t have to be that way, though, at least if the wonky part is one of the many computer modules found in most cars made in the last few decades. Sometimes they can be repaired, as with this engine control module from a Ford F350 pickup. Admittedly, [jeffescortlx] got pretty lucky with this module, which with its trio of obviously defective electrolytics practically diagnosed itself. He also had the advantage of the module’s mid-90s technology, which still relied heavily on through-hole parts, making the repair easier.

Unfortunately, his luck stopped there, as the caps had released the schmoo and corroded quite a few traces on the PCB. Complicating the repair was the conformal coating on everything, a common problem on any electronics used in rough environments. It took a bit of probing and poking to locate all the open traces, which included a mystery trace far away from any of the leaky caps. Magnet wire was used to repair the damaged traces, the caps were replaced with new ones, and everything got a fresh coat of brush-on conformal coating.

Simple though they may be, we really enjoy these successful vehicle module repairs because they give us hope that when the day eventually comes, we’ll stand a chance of being able to perform some repair heroics. And it’s nice to know that something as simple as fixing a dead dashboard cluster can keep a car out of the crusher.

Give Your SMD Components a Lift

22 Octubre 2024 at 23:00

When you are troubleshooting, it is sometimes useful to disconnect a part of your circuit to see what happens. If your new PCB isn’t perfect, you might also need to add some extra wires or components — not that any of us will ever admit to doing that, of course. When ICs were in sockets, it was easy to do that. [MrSolderFix] shows his technique for lifting pins on SMD devices in the video below.

He doesn’t use anything exotic beyond a microscope. Just flux, a simple iron, and a scalpel blade. Oh, and very steady hands. The idea is to heat the joint, gently lift the pin with the blade, and wick away excess solder. If you do it right, you’ll be able to put the pin back down where it belongs later. He makes the sensible suggestion of covering the pad with a bit of tape if you want to be sure not to accidentally short it during testing. Or, you can bend the pin all the way back if you know you won’t want to restore it to its original position.

He does several IC pins, but then shows that you need a little different method for pins that are near corners so you don’t break the package. In some cases for small devices, it may work out better to simply remove them entirely, bend the pins as you want, and then reinstall the device.

A simple technique, but invaluable. You probably don’t have to have a microscope if you have eagle eyes or sufficient magnification, but the older you get, the more you need the microscope.

Needless to say, you can’t do this with BGA packages. SMD tools used to be exotic, but cheap soldering stations and fine-tipped irons have become the norm in hacker’s workshops.

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