Dumpster diving is a time honored tradition in the hacking community. You can find all sorts of interesting hardware in the trash, and sometimes it’s even fully functional. But even the broken gadgets are worth taking back to your lair to strip for parts. If you’re as lucky as [Jamz], you might be able to mash a few devices together and turn them into something usable.
In this case, [Jamz] scored a LG 27UK650 monitor with a cracked display and a Dell OptiPlex 7440 “All-in-One” computer that was DOA. Separately these two pieces of gear were little more than a pile of spare parts waiting to be liberated. But if the control board could be salvaged from the monitor, and the working LCD pulled from the Dell…
After taking everything apart, [Jamz] made a frame for this new Frankenstein monitor using pieces of aluminum channel from the hardware store and 3D printed side panels. With the Dell LCD mounted in the skeletal frame, the control board from the LG monitor was bolted to the back and wired in. Finally the center section of the LG monitor’s back panel was cut out and mounted to the new hybrid display with a 3D printed frame.
Admittedly, these were some pretty solid finds as far as trash goes. You won’t always be so lucky. But if you can keep an open mind, the curb is littered with possibilities. How about some impressive home lighting that started life as a cracked flat screen TV?
Unfortunately not all consumers place high value on the security of their computers, but one group that tends to focus on security are businesses with a dedicated IT group. When buying computers for users, these groups tend to have higher demands, like making sure the Intel Management Engine (IME) has been disabled. To that end, Reddit user [netsec_burn] has outlined a pretty simple method to where “normal people” can purchase one of these IME-disabled devices for themselves.
For those unfamiliar with the IME, it is a coprocessor on all Intel devices since around 2007 that allows access to the memory, hard drive, and network stack even when the computer is powered down. Intel claims it’s a feature, not a bug, but it’s also a source of secret, unaudited code that’s understandably a desirable target for any malicious user trying to gain access to a computer. The method that [netsec_burn] outlined for getting a computer with the IME disabled from the factory is as simple as buying a specific Dell laptop, intended for enterprise users, and selecting the option to disable the IME.
Of course Dell warns you that you may lose some system functionality if you purchase a computer with the IME disabled, but it seems that this won’t really effect users who aren’t involved in system administration. Also note that this doesn’t remove the management engine from the computer. For that, you’ll need one of only a handful of computers made before Intel made complete removal of the IME impossible. In the meantime, it’s good to see that at least one company has a computer available that allows for it to be disabled from the factory.
Proprietary components are the bane of anyone who dares to try and repair their own hardware. Nonstandard sizes, lack of labeling or documentation, and unavailable spare parts are all par for the course. [Jason] was unlucky enough to have an older Dell computer with a broken, and proprietary, cooling fan on it and had to make some interesting modifications to replace it.
The original fan had three wires and was controlled thermostatically, meaning that a small thermistor would speed up the the fan as the temperature increased. Of course, the standard way of controlling CPU fans these days is with PWM, so he built a circuit which essentially converts the PWM signal from the motherboard into a phantom thermistor. It’s even more impressive that it was able to be done with little more than a MOSFET and a Zener diode.
Unfortunately, there was a catch. The circuit only works one way, meaning the fan speed doesn’t get reported to the motherboard and the operating system thinks the fan has failed. But [Jason] simply disabled the warning and washed his hands of that problem. If you don’t want to use a CPU fan at all, you can always just dunk your entire computer in mineral oil.
Sometimes we find projects that border on the absurd but are too cool to pass up. The Comprinter is exactly that. [Mason Stooksbury] had a dream. An all-in-one scanner printer that was also a computer. What would turn heads more than walking into a hackerspace with a printer, plugging your headphones in, then opening up the top to reveal a monitor?
[Mason’s] dream became possible when friends gave him some old laptops and a dead Kodak printer. After going through the laptops, he picked a Dell Inspiron 1440 to be the donor machine. The printer and laptop were both carefully stripped down. [Mason’s] goal for the project was to build a “beautiful” printer/computer. No bodges allowed. He spent most of his time planning out how to mount the motherboard and display inside the scanner section of the chassis.
The actual assembly was quite fiddly. Working with only an inch or so of clearance, [Mason] installed standoffs for the motherboard and display. He to do all this without breaking the wires for the display and WiFi antennas.
Once the main parts of the laptop were assembled, [Mason] completed the build with a nine-port USB hub, some internally mounted speakers and a USB keyboard mounted in the paper tray. The twelve-hour operation was a complete success. What looks to be a cheap inkjet actually hides a complete laptop running Xubuntu. The only downside is that the printer doesn’t actually print, but [Mason] is quick to note that if the printer hadn’t been broken in the first place, it would work fine — all the modifications are in the scanner section.
We’ve seen some wild casemods over the years, including a Nintendo in a toaster, a modern PC stuffed into an original Xbox, and Raspberry Pi’s stuffed into just about everything.
The good thing about using a server-grade machine as your desktop is having raw computing power at your fingertips. The downside is living next to a machine that sounds like a fleet of quadcopters taking off. Luckily, loud server fans can be replaced with quieter units if you know what you’re doing.
Servers are a breed apart from desktop-grade machines, and are designed around the fact that they’ll be installed in some kind of controlled environment. [Juan] made his Dell PowerEdge T710 tower server a better neighbor by probing the PWM signals to and from the stock Dell fans; he found that the motherboard is happy to just receive a fixed PWM signal that indicates the fans are running at top speed. Knowing this, [Juan] was able to spoof the feedback signal with an ATtiny85 and a single line of code. The noisy fans could then be swapped for desktop-grade fans; even running full-tilt, the new fans are quieter by far and still keep things cool inside.
But what to do with all those extra fans? Why not team them up with some lasers for a musical light show?
If you’ve ever had a laptop charger die, you know that they can be expensive to replace. Many laptops require you to use a ‘genuine’ charger, and refuse to boot when a knock off model is used. Genuine chargers communicate with the laptop and give information such as the power, current, and voltage ratings of the device. While this is a good safety measure, ensuring that a compatible charger is used, it also allows the manufacturers to increase the price of their chargers.
[Xuan] built a device that spoofs this identification information for Dell chargers. In the four-part series (1, 2, 3, 4), the details of reverse engineering the communications and building the spoofer are covered.
Dell uses the 1-Wire protocol to communicate with the charger, and [Xuan] sniffed the communication using a MSP430. After reading the data and verifying the CRC, it could be examined to find the fields that specify power, voltage, and current.
Next, a custom PCB was made with two Dell DC jacks and an MSP430. This passes power through the board, but uses the MSP430 to send fake data to the computer. The demo shows off a 90 W adapter pretending to run at 65 W. With this working, you could power the laptop from any supply that can meet the requirements for current and voltage.
[Troy Wright] acquired a lot of twenty broken Dell Axim PDAs. This type hardware was quite popular a decade ago, but looks archaic when compared to a modern cell phone. That’s why he was able to get them for a song. After a bit of work he managed to resurrect eight of the units, but was dismayed to find there’s no published method for controlling the back light from software. For some reason this is a deal-breaker for his project. But he knew it was possible because there are some apps for the device which are able to set the back light level. So he found out how to do it by reverse engineering the software.
The trick is to get a hold of the code. Since it’s not open source [Troy] used IDA, a graphical disassember and debug suite. He had some idea of what he was hunting for as the Windows CE developer documentation does mention a way to directly control the graphical hardware independently from the display driver. A few hours of pawing through assembly language, setting break points, and testing eventually led him to the solution.