Repair Hacks

634 Articles

Classic Heathkit OL-1 Scope Gets Some TLC

October 23, 2024 by 9 Comments

These days, not only are oscilloscopes very common, but even a cheap instrument today would have been the envy of the world’s greatest labs not that long ago. But back in the day, the home experimenter basically had two choices: buy a surplus scope that a big company was getting rid of or build a Heathkit. [Radiotvphononut] bought an old Heathkit OL-1 scope at an estate sale and set about putting it back in service.

If you are used to a modern scope, you’ll be amazed at how simple a scope like this can be. A handful of tubes and a CRT is the bulk of it. Of course, the OL-1 is an analog scope with a 400 kHz bandwidth. It did, however, have two channels, which was a rarity at the time.

The OL-1 was sold for a few years up to 1956 and cost about $30 as a kit. There was a version with a larger screen (five whole inches) that cost an extra $40, so you can bet there were more OL-1s sold since $40 was a big ask in 1956. While they don’t seem like much today, you were probably the envy of the ham club in 1956 when you lugged this in for show and tell.

This is a long video, but it pays off at the end. Overall, this was a more capable scope than the $66 scope from 10 years earlier we looked at. Did you ever wonder how people visualized signals before the CRT? Funny, we did too.

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Give Your SMD Components A Lift

October 22, 2024 by 10 Comments

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.

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MOTU Audio Interface Resurrected After Some Reverse Engineering

October 18, 2024 by 8 Comments

These days, when something electronic breaks, most folks just throw it away and get a new one. But as hackers, we prefer to find out what the actual problem is and fix it. [Bonsembiante] took that very tack when a MOTU brand audio interface wasn’t booting. As it turns out, a bit of investigative work led to a simple and viable fix.

The previous owner had tried to get the unit fixed multiple times without success. When it ended up on [Bonsembiante]’s bench, reverse engineering was the order of the day. Based around an embedded Linux system, there was lots to poke and prod at inside, it’s just that… the system wasn’t booting, wasn’t showing up over USB or Ethernet, or doing much of anything at all.

Extracting the firmware only revealed that the firmware was actually valid, so that was a dead end. However, after some work following the boot process along in Ghidra, with some external help, the problem was revealed. Something was causing the valid firmware to fail the bootloader’s checks—and with that fixed, the unit booted. You’ll have to read the article to get the full juicy story—it’s worth it!

We’ve seen [Bonsembiante’s] work here before, when they turned an old ADSL router into a functioning guitar pedal. Video after the break.

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Repairing A Component On A Flex Connector

October 11, 2024 by 15 Comments

It used to be you could crack open a TV or radio and really work on the components inside. The smallest thing in there was maybe a disc capacitor a little smaller than your pinky’s nail. Nowadays, consumer electronic boards are full of tiny SMD components. Luckily [StezStix Fix?] has a microscope and the other tools you need. Someone sent him an Amazon Echo Show with a bad touchscreen. Can it be fixed?

The video below shows that it can, but there’s a twist. The bad capacitor was mounted on one of those flexible PCB cables that are so hard to work with. It is hard enough not to damage these when you aren’t trying to remove and replace a component from the surface of the cable.

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Braun TS2 Radio Turns 68, Gets Makeover

October 9, 2024 by 7 Comments

The Braun TS2 radio was a state-of-the art tube set in 1956. Today it still looks great, but unsurprisingly, the one that [Manuel Caldeier] has needed a little tender loving care. The table radio had a distinct style for its day and push-buttons. However, the dial glass and the speaker grill needed replacement. Even more interesting, the radio has a troublesome selenium rectifier, giving him the perfect chance to try out his new selenium rectifier solid-state replacement.

The radio is as good-looking inside as it is outside. You can tell that this isn’t his first restoration, as he has several tricks to test things at different stages of the project.

While the radio looked good, it smelled of smoke, which required a big effort to clean. The dial glass was intact enough for him to duplicate it in a graphic program and print it on a transparent adhesive sticker. With a deep breath, he removed the original markings from the glass so he could add the sticker to it. That didn’t work because the label needed cutouts. So now he is waiting for a piece of acrylic that will have the art UV printed on it.

We want to see the next part as we imagine the radio sounds as good as it looks when it is working. If you want to know more about the rectifier replacement, we covered that earlier. Even years later, Braun would have a clean aesthetic.

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Laptop GPU Upgrade With Just A Little Reballing

October 2, 2024 by 5 Comments

Modern gaming laptops are in an uncomfortable spot – often too underpowered for newest titles, but too bulky to be genuinely portable. It doesn’t help they’re not often upgradeable, so you’re stuck with what you’ve bought – unless, say, you’re a hacker equipped some tools for PCB reflow? If that’s the case, welcome to [TechModLab]’s video showing you the process of upgrading a laptop’s soldered-on NVIDIA GPU, replacing the 3070 chip with a 3080.

You don’t need much – the most exotic tool is a BGA rework station, holding the mainboard steady&stiff and heating a specific large chip on the board with an infrared lamp from above. This one is definitely a specialty tool, but we’ve seen hackers build their own. From there, some general soldering tools like flux and solder wick, a stencil for your chip, BGA balls, and a $20 USB-C hotplate are instrumental for reballing chips – tools you ought to have.

Reballing was perhaps the hardest step of the journey – instrumental for preparing the GPU before the transplant. Afterwards, only a few steps were needed – poking a BGA ball that didn’t connect, changing board straps to adjust for the new VRAM our enterprising hacker added alongside the upgrade, and playing with the driver process install a little. Use this method to upgrade from a lower-end binned GPU you’re stuck with, or perhaps to repair your laptop if artifacts start appearing – it’s a worthwhile reminder about methods that laptop repair shops use on the daily.

Itching to learn more about BGAs? You absolutely should read this article series by our own [Robin Kearey]. We’ve mostly seen reballing used for upgrading RAM on laptop and Raspberry Pi boards, but seeing it being used for an entire laptop is nice – it’s the same technique, just scaled up, and you always can start by practicing at a smaller scale. Now, it might feel like we’ve left the era of upgradable GPUs on laptops, and today’s project might not necessarily help your worries – but the Framework 16 definitely bucks the trend.

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Screen caps of upgraded BBC Micro, and OS 9 code

BBC Micro: A Retro Revamp With The 68008 Upgrade

October 1, 2024 by 3 Comments

The BBC Microcomputer, launched in the early 1980s, holds a special place in computing history. Designed for educational purposes, it introduced a generation to programming and technology. With its robust architecture and community-driven modifications, the BBC Micro remains a beloved project for retro computing enthusiasts. [Neil] from Retro4U has been delving into this classic machine, showcasing the fascinating process of repairing and upgrading his BBC Micro with a 68008 CPU upgrade.

Last week, [Neil] shared his progress, unveiling advancements in his repairs and upgrades. After tackling a troublesome beep issue, he successfully managed to get the BBC running with 32 KB of functional memory, allowing him to boot into BASIC. But he wasn’t stopping there. With ambitions set on installing the 68008 CPU, [Neil]’s journey continued.

The 68008 board offers significant enhancements, including multitasking capabilities with OS-9 and its own hard drive and floppy disk controller. However, [Neil] quickly encountered challenges; the board’s condition revealed the usual broken capacitors and a few other faulty components. After addressing these issues, [Neil] turned his attention to programming the necessary ROM for OS-9.

Looking to get your hands dirty? [Neil] has shared a PDF of the upgrade circuit diagram. You can also join the discussion with fellow enthusiasts on his Discord channel, linked in the video description.

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