Fixing A Milltronics ML15 CNC Lathe Despite The Manufacturer’s Best Efforts

November 20, 2025 by Maya Posch 10 Comments

When you’re like [Wes] from Watch Wes Work fame, you don’t have a CNC machine hoarding issue, you just have a healthy interest in going down CNC machine repair rabbit holes. Such too was the case with a recently acquired 2001 Milltronics ML15 lathe, that at first glance appeared to be in pristine condition. Yet despite – or because of – living a cushy life at a college’s workshop, it had a number of serious issues, with a busted Z-axis drive board being the first to be tackled.

The Glentek servo board that caused so much grief. (Credit: Watch Wes Work, YouTube)

The identical servo control board next to it worked fine, so it had to be an issue on the board itself. A quick test showed that the H-bridge IGBTs had suffered the typical fate that IGBTs suffer, violently taking out another IC along with them. Enjoyably, this board by one Glentek Inc. did the rebranding thing of components like said IGBTs, which made tracking down suitable replacements an utter pain that was eased only by the desperate communications on forums which provided some clues. Of course, desoldering and testing one of the good IGBTs on the second board showed the exact type of IGBT to get.

After replacing said IGBTs, as well as an optocoupler and other bits and pieces, the servo board was good as new. Next, the CNC lathe also had a busted optical encoder, an unusable tool post and a number of other smaller and larger issues that required addressing. Along the way the term ‘pin-to-pin compatible’ for a replacement driver IC was also found to mean that you still have to read the full datasheet.

Of the whole ordeal, the Glentek servo board definitely caused the most trouble, with the manufacturer providing incomplete schematics, rebranding parts to make generic replacements very hard to find and overall just going for a design that’s interesting but hard to diagnose and fix. To help out anyone else who got cursed with a Glentek servo board like this, [Wes] has made the board files and related info available in a GitHub repository.

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Using The Pyroelectric Effect To Identify Broken MLCC Capacitors

November 15, 2025 by Maya Posch 6 Comments

Vintage computer hardware can fail in a variety of fascinating ways, with [Bits und Bolts] dealing with an interesting failure mode, in the form of degraded MLCC capacitors on Voodoo 2 graphics cards. These little marvels of miniaturized surface-mount technology enable the placement of ceramic capacitors with very little space required, but as they degrade over time or due to physical damage, they can cause big issues in a circuit.

In the case of the two Voodoo 2 GPUs that [Bits und Bolts] was trying to fix, the clue that something was wrong was graphical glitches, which seemed to be related to something dragging down the 5V rail. Using the standard ‘inject voltage and see what gets hot’ method, he discovered a couple of dead MLCCs and replaced them. But something was still dragging the rail down. Unfortunately, whatever it was wasn’t enough to heat up the part in question, and no sane person wants to desolder hundreds or even thousands of MLCCs on a PCB and see whether it makes a difference.

Ultimately, the pyroelectric effect was used to hunt down the culprit, saving countless hours of work. This is a property of certain naturally electrically polarized crystals, in which the material generates a voltage when heated or cooled. Materials like that used in MLCCs, for example.

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Recreating The Destroyed Case Of LGR’s Rare 1980s Laptop

November 9, 2025 by Maya Posch 4 Comments

A while back [Clint Basinger] of Lazy Game Reviews fame purchased a rare 1980s Halikan laptop. When he received the parcel, at first glance, everything seemed in order. Upon opening the original laptop bag, however, it was found that the combination of the heavy power supply in a side pocket and the brittle plastic of the laptop’s case had turned the latter into sad fragments of regret. At the time [Clint] wasn’t sure what he’d do, but fortunately [polymatt] stepped in with the joyful news: we can rebuild it; we have the technology.

Obviously, the sad plastic fragments of the original case weren’t going together again in any meaningful way, nor would this have been helpful, but the pieces, along with photos of an intact laptop, helped with the modelling of a digital model of the case. One model and one 3D printer is all you need. For this case, the print used ABS, with gaps between the segmented prints filled with an ABS slurry, as the case was too large to be printed without jumping through some hoops.

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Toasty Subwoofer Limps Back To Life

October 11, 2025 by Al Williams 6 Comments

[JohnAudioTech] noticed there was no bass on the TV at his parents’ house. That led to the discovery of a blown fuse and a corresponding repair. When he opened it up, he could smell that something had gone on in the amplifier. You can follow the repair in the video below.

His first theory was that some glue became conductive and shorted the power rails. We were skeptical, to be honest. When he fed power to it through a current limiter, he could hear a sizzling noise and even see a little glowing from the hot component.

Disassembly ensued. Removing the suspect components showed some seriously burned components and some charring under a switching transistor. The capacitors looked much worse for wear, and the PCB needed some wires to jumper burned conductors.

At the end, there was thumping, so it seems the surgery was a success. However, testing blew a fuse again, which made us nervous. Still, seems to work if you don’t drive it too hard.

We always enjoy watching a teardown, and if there’s a repair too, that’s even better.

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Apple’s Continuing Failing Repair Score With The AirPods Pro 3

October 5, 2025 by Maya Posch 18 Comments

It takes quite a bit of effort to get a 0 out of 10 repairability score from iFixit, but in-ears like Apple’s AirPods are well on course for a clean streak there, with the AirPod Pro 3 making an abysmal showing in their vitriolic teardown video alongside their summary article. The conclusion is that while they are really well-engineered devices with a good feature set, the moment the battery wears out it is effectively e-waste. The inability to open them without causing at least some level of cosmetic damage is bad, and that’s before trying to glue the device back together. Never mind effecting any repairs beyond this.

Worse is that this glued-together nightmare continues with the charging case. Although you’d expect to be able to disassemble this case for a battery swap, it too is glued shut to the point where a non-destructive entry is basically impossible. As iFixit rightfully points out, there are plenty of examples of how to do it better, like the Fairbuds in-ears. We have seen other in-ears in the past that can have some maintenance performed without having to resort to violence, which makes Apple’s decisions here seem to be on purpose.

Although in the comments to the video there seem to be plenty of happy AirPod users for whom the expected 2-3 year lifespan is no objection, it’s clear that the AirPods are still getting zero love from the iFixit folk.

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A Walk Down PC Video Card Memory Lane

September 28, 2025 by Al Williams 30 Comments

These days, video cards are virtually supercomputers. When they aren’t driving your screen, they are decoding video, crunching physics models, or processing large-language model algorithms. But it wasn’t always like that. The old video cards were downright simple. Once PCs gained more sophisticated buses, video cards got a little better. But hardware acceleration on an old-fashioned VGA card would be unworthy of the cheapest burner phone at the big box store. Not to mention, the card is probably twice the size of the phone. [Bits and Bolts] has a look at several old cards, including a PCI version of the Tseng ET4000, state-of-the-art of the late 1990s.

You might think that’s a misprint. Most of the older Tseng boards were ISA, but apparently, there were some with the PCI bus or the older VESA local bus. Acceleration here typically meant dedicated hardware for handling BitBlt and, perhaps, a hardware cursor.

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Reviving A Scrapped Sound Blaster 2.0 ISA Soundcard

September 22, 2025 by Maya Posch 7 Comments

What do you do when you find a ISA Sound Blaster 2.0 card in a pile of scrap? Try to repair the damage on it to give it a second shot at life, of course. This is what [Adrian Black] did with one hapless victim, with the card in question being mostly in good condition minus an IC that had been rather rudely removed. The core Creative CT1336A and Yamaha YM3812 ICs were still in place, so the task was to figure out what IC was missing, find a replacement and install it.

The CT1350 is the final revision of the original 8-bit ISA Sound Blaster card, with a number of upgrades that makes this actually quite a desirable soundcard. The CT1350B revision featured here on a card from 1994 was the last to retain compatibility with the C/MS chips featured on the original SB card. After consulting with [Alex] from the Bits und Bolts YT channel, it was found that not only is the missing IC merely an Intel 8051-based Atmel MCU, but replacements are readily available. After [Alex] sent him a few replacements with two versions of the firmware preflashed, all [Adrian] had to do was install one.

Before installation, [Adrian] tested the card to see whether the expected remaining functionality like the basic OPL2 soundchip worked, which was the case. Installing the new MCU got somewhat hairy as multiple damaged pads and traces were discovered, probably because the old chip was violently removed. Along the way of figuring out how important these damaged pads are, a reverse-engineered schematic of the card was discovered, which was super helpful.

Some awkward soldering later, the card’s Sound Blaster functionality sprung back to life, after nudging the volume dial on the card up from zero. Clearly the missing MCU was the only major issue with the card, along with the missing IO bracket, for which a replacement was printed after the video was recorded.

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