Autopsy Of A Freshly Cooked 10Gbit SFP+ Network Adapter

With the advent of affordable 2.5 Gbit, 5 Gbit, and 10 Gbit consumer networking gear, more and more people are taking advantage of these higher networking speeds, with [This Does Not Compute] having used 10 Gbit SFP+ modules over regular Cat-5e copper to connect to a NAS in the next room. Only problem was that after a while these SFP+ modules began to start dropping frames. On taking a closer look at these modules, he found that they were running pretty hot: 40°C while idle. A teardown of one of these modules showed severe discoloration due to heat.

Side view of the SFP+ module's PCB. (Credit: This Does Not Compute, YouTube)
Side view of the SFP+ module’s PCB. (Credit: This Does Not Compute, YouTube)

Inside these 10Gbit modules is the Marvell-branded Alaska X 88X3310/40P PHY, which despite the ‘low-power’ claims have a metal heatsink glued onto the actual IC and thermally coupled to the module’s metal enclosure. The other side of the PCB was quite discolored, further indicating how hot these modules run in operation. Some digging revealed that this can go up to around 2.5 watts.

Perhaps the most fascinating part of this teardown is the discovery of an 8051-based MCU that’s responsible for telling the switch the module is put into that it is a 30-meter multi-mode fiber module, presumably for compatibility purposes. It’s definitely an interesting feature of these FS-branded SFP+ modules.

These old modules were replaced with Wiitek-branded modules that are supposed to use only up to around 1.5 watts in operation courtesy of a newer chipset, in the hope that these wouldn’t fry themselves. At idle these do however still run at 30 °C. As noted in the comments, it might be a good idea to have active airflow over high-speed networking gear like this, as they generally can get pretty hot and sometimes crispy.

The final solution for the video’s networking problem was to just run single-mode fiber to the room and use appropriate SFP+ modules for that, also because these run noticeably cooler. If you still have room in your cable ducts, that would seem to be the optimal solution.

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The Repair Nightmare That Are Smart Rings

In the quest to make every wearable device ‘smart’, a lot of electronics along have to be crammed in very small spaces, along with ways to make them resistant to environments that our bodies do not mind, like getting hit by a rainstorm or simply washing our hands. These two factors combined make especially devices like smart rings an interesting case study for repairability, with [iFixit] recently taking apart a modern Oura smart ring to assess its e-waste factor after the built-in battery dies.

The tiny 10.5 mAh Lipo cell in the Oura Ring 5. (Credit: iFixit)
The tiny 10.5 mAh Lipo cell in the Oura Ring 5. (Credit: iFixit)

The subject of the teardown video is the Oura Ring 5, a $400 smart ring that’s designed to track your vitals much like a wrist-worn fitness tracker — just in a much smaller package. This metal-and-epoxy sandwich can definitely survive a good rain shower and washing of hands, but to get to the internals rather forceful methods were needed, unlike previous Oura and Samsung smart rings where some applied heat was enough.

In the Ring 5’s case even more heat was needed to make the inner ring start to slide out, but by that point the Li-ion battery inside had already popped from the heat. The inner ring then got stuck and more violence was required to continue the disassembly and get to the super-tiny, 10.5 mAh battery. Of course, at this point the smart ring really won’t be getting back together, never mind still work or be waterproof, which is a central issue with these smart rings.

With the EU’s February 2027 deadline for user-replaceable batteries looming on the horizon, it’ll be interesting to see whether devices like this can squeeze into an exception category, or whether manufacturers will have to massively redesign or stop selling these devices to this rather large market. So far this particular regulation has already forced Nintendo to make a special Switch 2 console for the EU.

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Teardown: ChargeTab Emergency Phone Charger

If you own a modern smartphone, there’s an excellent chance that its battery has run dangerously low on you at least a few times. Murphy’s Law dictates that this will naturally occur at the worst possible moment, say when you need to make an important phone call or when you’re lost and need to navigate home.

With this in mind, it’s not hard to see how a product like the ChargeTab would have a certain appeal. A small $10 USD device that you can keep in the car or pack in a bag that’s always available to charge your phone in an emergency.

Because it’s not meant to be used regularly — indeed it may never get used at all — it’s not completely unreasonable that such a device would only be good for one or two charges before its spent and must be replaced. It’s a bit like keeping a road flare in the car; it’s unlikely you’ll ever use the thing, but if you do, it only needs to work once.

But then what? According to ChargeTab, once the gadget has depleted its internal ~3,000 mAh battery it cannot be recharged and is no longer usable. Now to be fair, they specifically tell you to not throw it in the trash. They’ll send you a free return label to ship it back to them, at which point it will be refurbished and put back into circulation. The company argues that this recycling program, combined with the fact that the batteries inside the ChargeTabs were supposedly diverted from landfills in the first place, makes their entire operation eco-friendly.

Yet here we have a pair of ChargeTabs that were thrown in the regular garbage and would have taken a one-way trip to the local landfill if it wasn’t for the fact that I habitually dig through garbage cans like a raccoon. So let’s take a look at what’s inside one of these emergency phone chargers and if the idea is as green as the company claims.

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Hear Ye, Hear Ye! The Magic Of The Scroll-Like Phone Which Wast Not!

When LG left the smartphone market, quite a number of strange devices were left behind. While some, like the Wing, made it to consumers, others did not. The strangest of these would have to be their rollable phone concept; a device which would expand by unrolling a portion of the screen like a scroll. This never made it to market, but one managed to make its way to [JerryRigEverything’s] workbench, and we are fortunate enough to see the insides of this strange device. 

There are a few interesting tidbits about the device before even entering the device. Very clearly this phone was ready to be sold, with a tidy user interface for expanding the display, and even animated wallpapers which expand with it. The display, when rolled onto the back of the device, sits behind a glass cover to keep it protected from debris, and can be used to take selfies with the larger sensors of the rear facing cameras. You can also see a bit of the track that the screen rolls on, hinting at what lies inside.

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Reverse-Engineering A Handheld Car Tire Pressure Gauge

The SDIC 8-bit MCU. (Credit: electronupdate, YouTube)
The SDIC 8-bit MCU. (Credit: electronupdate, YouTube)

In this wonderful world of MEMS technology, sensor technology has been downsized and reduced in cost to the point where you can buy a car tire pressure sensor for less than $3 USD on a site like AliExpress. Recently [electronupdate] got his mittens on one of these items to take a look inside, and compare it against his trusty old mechanical tire pressure gauge.

Perhaps unsurprisingly, there isn’t a whole lot inside these devices once you pop them open to reveal the PCB. The MEMS device is a tiny device at the top, which has the pressurized air from the tire guided to it. The small hole inside the metal can leads to the internals that consist of a thin diaphragm with four piezoresistors that enable measurements on said diaphragm from which pressure can be determined.

Handling these measurements and displaying results on the small zebra connector-connected LCD is an 8-bit MCU manufactured by Chinese company SDIC. Although the part number on the die doesn’t lead to any specific part on the SDIC site, similar SDIC parts have about 256 bytes of SRAM and a few kB of one-time programmable ROM.

This MCU also integrates the clock oscillator, thus requiring virtually no external parts to work. Finally, its sigma-delta ADC interacts with the MEMS device, rounding out a very simple device that’s nevertheless more than accurate enough for a spot check as well as quite portable.

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Teardown Of A 2026 LEGO SMART Brick

LEGO SMART brick from its side. (Credit: EvilmonkeyzDesignz, YouTube)
LEGO SMART brick from its side. (Credit: EvilmonkeyzDesignz, YouTube)

At the beginning of March this year LEGO released their new SMART brick, which looks like a 2×4 stud brick and is filled to the brim with sensors, LEDs, NFC and Bluetooth functionality, as well as a purported custom ASIC. The central idea behind it appears to be to add a lot of interactivity to LEGO builds while allowing for mesh-style communication with other SMART bricks. Naturally, this makes it a great subject for a teardown, which is what [EvilmonkeyzDesignz] over on YouTube did in a recent video.

Normally the only way you can purchase one of these new bricks is by buying them as part of a ‘Smart Play’ set, but someone was selling singular bricks on EBay. As the brick is inductively recharged, it’s pretty well-sealed, requiring a fairly destructive opening method.

Directly below the transparent top is a speaker, with the opposing PCB on the main body containing a microphone as well as a number of RGB LEDs. On the opposite side of this PCB we find the photo sensor, but to get to this part of the PCB the copper wires that wrap around the entire main assembly have to be disconnected from the PCB’s side pads with some force as they’re apparently pressed in place without the use of solder.

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AirTag Has Hole Behind The Battery? It’s Likely Been Silenced

Apple AirTags have speakers in them, and the speaker is not entirely under the owner’s control. [Shahram] shows how the speaker of an AirTag can be disabled while keeping the device watertight. Because AirTags are not intended to be opened or tampered with, doing so boils down to making a hole in just the right place, as the video demonstrates.

By making a hole in just the right place, the speaker can be disabled while leaving water resistance intact.

How does putting a hole in the enclosure not compromise water resistance? By ensuring the hole is made in an area that is already “inside” the seal. In an AirTag, that seal is integrated into the battery compartment.

Behind the battery, the enclosure has a small area of thinner plastic that sits right above the PCB, and in particular, right above the soldered wire of the speaker. Since this area is “inside” the watertight seal, a hole can be made here without affecting water resistance.

Disabling the speaker consists of melting through that thin plastic with a soldering iron then desoldering the (tiny) wire and using some solder wick to clean up. It’s not the prettiest operation, but there are no components nor any particularly heat-sensitive bits in that spot. The modification has no effect on water resistance, and isn’t even visible unless the battery is removed.

In the video below, [Shahram] uses a second generation AirTag to demonstrate the mod, then shows that the AirTag still works normally while now being permanently silenced.

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