Fail Of The Week: A Potentially Lethal Tattoo Removal Laser Power Supply

March 24, 2024 by Dan Maloney 7 Comments

Caveat emptor is good advice in general, but in the wilds of eBay, being careful with what you buy could be life-saving. To wit, we present [Les Wright]’s teardown and very ginger power-up of an eBay tattoo-removal laser power supply.

Given that [Les] spent all of around $100 on this widowmaker, we’re pretty sure he knew what he was getting himself into. But he likely wasn’t quite prepared for the scale of the sketchiness this thing would exhibit. The deficiencies are almost too many to number, starting with the enclosure, which is not only made completely of plastic but assembled from individual sheets of flat plastic stock that show signs of being glued together by hand. Even the cooling water tank inside the case is pieced together this way, which probably led to the leaks that corroded the PCBs. Another assembly gem is the pair of screws the big energy storage capacitor is jammed under, presumably to hold it in place — because nothing says quality like a BOM that can’t spring for a couple of cable ties. Click through the break to read more and see the video.

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Custom Fume Hood For Safe Electroless Plating

October 22, 2023 by Bryan Cockfield 10 Comments

There are plenty of chemical processes that happen commonly around the house that, if we’re really following safety protocols to the letter, should be done in a fume hood. Most of us will have had that experience with soldering various electronics, especially if we’re not exactly sure where the solder came from or how old it is. For [John]’s electroless plating process, though, he definitely can’t straddle that line and went about building a fume hood to vent some of the more harmful gasses out of a window.

This fume hood is pretty straightforward and doesn’t have a few of the bells and whistles found in commercial offerings, but this process doesn’t really require things like scrubbing or filtering the exhaust air so he opted to omit these pricier and more elaborate options. What it does have, though, is an adjustable-height sash, a small form factor that allows it to easily move around his shop, and a waterproof, spill-collecting area in the bottom. The enclosure is built with plywood, allowing for openings for an air inlet, the exhaust ducting, and a cable pass-through, and then finished with a heavy-duty paint. He also included built-in lighting and when complete, looks indistinguishable from something we might buy from a lab equipment supplier.

While [John] does admit that the exhaust fan isn’t anything special and might need to be replaced more often than if he had gone with one that was corrosion-resistant, he’s decided that the cost of this maintenance doesn’t outweigh the cost of a specialized fan. He also notes it’s not fire- or bomb-proof, but nothing he’s doing is prone to thermal anomalies of that sort. For fume hoods of all sorts, we might also recommend adding some automation to them so they are used any time they’re needed.

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BBC Master 128 Revealed

May 28, 2023 by Al Williams 12 Comments

[Adrian] comments that the BBC Master 128 is a rare 8-bit computer, and we agree — we couldn’t remember hearing about that particular machine, although the BBC series is quite familiar. The machine has a whopping 128 K of RAM, quite a bit for those days. It also had a 6502 variant known as the 65C12, which has an extra pin compared to a 6502 and doesn’t use the same clock arrangement. A viewer sent him one of these machines, which apparently was used in the BBC studios. You can see this rare beauty in the video below.

The computer has a very nice-looking keyboard that includes a number pad. There are also expansion ports for printers and floppy disk drives. It has some similarities to a standard BBC computer but has a number of differences externally and internally.

Of course, we were waiting for the teardown about 15 minutes in. There were some corroded batteries but luckily, they didn’t do much damage. The power supply had a burned smell. Cracking it open for inspection was a good time to convert the power supply to run on 120 V, too.

After some power supply repair, it was time to power the machine up. The results were not half bad. It started up with a cryptic error message: “This is not a language.” Better than a dead screen. The keyboard wasn’t totally working, though. A bit of internet searching found that the error happens when the battery dies and the machine loses its configuration.

More walkthroughs will take a bit more work on the keyboard. But we were impressed it came up as far as it did, and we look forward to a future installment where the machine fully starts up.

[Adrian] mentioned the co-processor slot accepting a Raspberry Pi, something we’ve talked about before. Or, add an FPGA and make the plucky computer think it is a PDP/11.

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Spilled OJ Does A Number On Zelda Game Boy Cartridge

October 13, 2021 by Tom Nardi 16 Comments

When [Taylor Burley] first opened up the cartridge for The Legend of Zelda: Oracle of Seasons, it certainly didn’t look like it had been dunked in corrosive orange juice. But looks can be deceiving, and while the game’s owner certainly did an admirable job of cleaning up the surface of the PCB, the cartridge was no longer functional. Clearly, this was a sticky situation.

After removing all of the components from the PCB, [Taylor] was quickly able to piece together what had happened. Despite the vigorous cleaning the game received after the spill, juice had found its way under each IC on the board. Left to sit in these nooks and crannies for who knows how long, the juice started to eat away at the traces on the PCB. Getting the game back up and running would naturally require considerable board repairs, but they don’t call him Solderking for nothing.

In the video below, you can see [Taylor] methodically scraping away the corrosion on the board before he starts recreating damaged connections with solid 30 gauge wire. Using tweezers and viewing the action through a digital microscope, he deftly bends the wire around to fit the shapes of the original traces and tacks the new conductors down with solder. He even goes ahead and repairs the traces that go to various test points on the cartridge; it’s a completely unnecessary extravagance, but we’re certainly not complaining. There’s a relaxing quality to watching him work, so we were in no rush to see his latest video end.

After fixing the board back up, he replaces all the components and takes it for a test drive on an original Game Boy Color. Confirming that Link’s 2001 outing is working as expected, he finishes the job with a few coats of spray-on conformal coating. With any luck, the next time this particular cartridge has to go face-to-face with some spilled juice, it will roll right off.

This isn’t the first time we’ve seen [Taylor] laboriously rebuild a Game Boy cartridge, and it certainly isn’t the first time we’ve seen him pull off some particularly impressive feats of soldering, either. His work always reminds us that patience and a steady hand can really do wonders.

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Bringing A Ruined Game Boy Cart Back To Life With Tons Of Soldering

September 15, 2021 by Lewin Day 17 Comments

Retro consoles and handhelds are full of nostalgia and happy memories for many. However, keeping these machines and their media going can be a difficult job at times. [Taylor] was challenged to rescue a copy of Kirby’s Dream Land for the original Game Boy, and set about the task.

The cartridge was badly corroded, with many of the traces eaten through, rendering the game inoperable. First, all the components were removed, and the board was cleaned. This allowed easy access to the traces across the whole board. Then, the job was to delicately remove some solder mask from the parts of the traces still remaining, and bridge the gaps with fine copper wire. Even worse, several vias were damaged, which [Taylor] tackled by feeding jumper wires through the board and executing a repair on each side.

It’s a simple enough repair for the experienced hand, but virtually magic to a retro gaming fan that doesn’t know how to solder. [Taylor] has given us a great example of how to deal with corroded carts properly, with enough detail to be quite educational to the beginner.

We’ve seen other great work in this vein too, like an Amiga 2000 brought back from a horrible creeping green death. If you’ve done your own retro rescue, be sure to drop us a line!

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Bodge Wire Saves A Vintage Mac SE/30 From The Heap

November 1, 2020 by Tom Nardi 20 Comments

Anyone who pokes around old electronics knows that age is not kind to capacitors. If you’ve got a gadget with a few decades on the clock, there’s an excellent chance that some of its capacitors are either on the verge of failure or have already given up the ghost. Preemptively swapping them out is common in retrocomputing circles, but what do you do if your precious computer has already fallen victim to a troublesome electrolytic?

That’s the situation that [Ronan Gaillard] recently found himself in when he booted up his Mac SE/30 and was greeted with a zebra-like pattern on the screen. The collected wisdom of the Internet told him that some bad caps were almost certainly to blame, though a visual inspection failed to turn up anything too suspicious. Knowing the clock was ticking either way, he replaced all the capacitors on the Mac’s board and gave the whole thing a good cleaning.

Unfortunately, nothing changed. This caught [Ronan] a bit by surprise, and he took another trip down the rabbit hole to try and find more information. Armed with schematics for the machine, he started manually checking the continuity of all the traces between the ROM and CPU. But again, he came up empty handed. He continued the process for the RAM and Glue Chip, and eventually discovered that trace A24 wasn’t connected. Following the course it took across the board, he realized it ran right under the C11 axial capacitor he’d replaced earlier.

Suddenly, it all made sense. The capacitor must have leaked, corroded the trace underneath in a nearly imperceptible way, and cut off a vital link between the computer’s components. To confirm his suspicions, [Ronan] used a bodge wire to connect both ends of A24, which brought the 30+ year old computer roaring back to life. Well, not so much a roar since it turns out the floppy drive was also shot…but that’s a fix for another day.

It seems like every hardware hacker has a bad capacitor story. From vintage portable typewriters to the lowly home router, these little devils and the damage they can do should always be one of the first things you check if a piece of hardware is acting up.

Fail Of The Week: How Not To Watercool A PC

June 17, 2020 by Dan Maloney 50 Comments

To those who choose to overclock their PCs, it’s often a “no expense spared” deal. Fancy heat sinks, complicated liquid cooling setups, and cool clear cases to show off all the expensive guts are all part of the charm. But not everyone’s pockets are deep enough for off-the-shelf parts, so experimentation with cheaper, alternatives, like using an automotive fuel pump to move the cooling liquid, seems like a good idea. In practice — not so much.

The first thing we thought of when we saw the title of [BoltzBrain]’s video was a long-ago warning from a mechanic to never run out of gas in a fuel-injected car. It turns out that the gasoline acts as a coolant and lubricant for the electric pump, and running the tank dry with the power still applied to the pump quickly burns it out. So while [BoltzBrain] expected to see corrosion on the brushes from his use of water as a working fluid, we expected to see seized bearings as the root cause failure. Looks like we were wrong: at about the 6:30 mark, you can see clear signs of corrosion on the copper wires connecting to the brushes. It almost looks like the Dremel tool cut the wire, but that green copper oxide is the giveaway. We suspect the bearings aren’t in great shape, either, but that’s probably secondary to the wires corroding.

Whatever the root cause, it’s an interesting tour inside a common part, and the level of engineering needed to build a brushed motor that runs bathed in a highly flammable fluid is pretty impressive. We liked the axial arrangement of the brushes and commutator especially. We wonder if fuel pumps could still serve as a PC cooler — perhaps changing to a dielectric fluid would do the trick.

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