In June, many owners of Samsung Blu Ray players found that their devices were no longer usable. Stuck in a boot loop, speculation was rife as to the cause of the issue. Now it seems that the issue has become clear – a badly formatted XML file may be responsible for the problems (via The Register).
The problem stems from the logging system that stores user data and passes it back to Samsung over the Internet. Which data is logged and sent back is managed by an XML file which contains the policy settings that control this behaviour. According to a source known only as
“Gary” “Gray”, the XML file posted on Samsung’s servers on June 18 featured a malformed list element. This caused a crash in the player’s main software routine, leading the player to reboot.
The failure was exacerbated by the fact that the XML file is parsed very early in the boot sequence, even before checking for firmware updates or a new XML file. This has prevented Samsung from rolling out an update or fix over the air, and is why the player gets stuck in a loop of continuous reboots.
Reportedly, the file can be found at this URL, though is now an updated version that shouldn’t brick players. Samsung have had to resort to a mail-in repair scheme, wherein technicians with service tools can manually remove the offending XML file from the player’s storage, allowing it to boot cleanly once again. While this shows our initial assumptions were off the mark, we’re glad to see a solution to the problem, albeit one that requires a lot of messing around.
[Thanks to broeckelmaier for the tip!]
Last Friday, thousands of owners of Samsung Blu Ray players found that their home entertainment devices would no longer boot up. While devices getting stuck in a power-cycling loop is not uncommon, this case stands out as it affected a huge range of devices all at the same time. Samsung’s support forum paints a bleak picture, with one thread on the issue stretching to 177 pages in just a week.
So what is going on, and what can be done to fix the problem? There’s a lot of conflicting information on that. Some people’s gear has started working again, others have not and there are reports of customers being told to seek in-person repair service. Let’s dive in with some wild speculation on the problem and circle back by commiserating about the woes of web-connected appliances.
Continue reading “Ask Hackaday: What Can Be Done With Your Bootlooping Blu-Ray?”
Optical drives are somewhat passe in 2019, with most laptops and desktops no longer shipping with the hardware installed. The power of the cloud has begun to eliminate the need for physical media, but that doesn’t mean the technology is any less marvellous. [Leslie Wright] and [Samuel Goldwater] took a deep dive into what makes the PS3’s optical drive tick, back in the heyday of the Blu Ray era.
The teardown starts by examining the layout of the assembly, and the parts involved. This is followed by a deep dive into an exploration of the triple-laser diode itself, There are tips on how to safely extract the delicate parts, which are highly sensitive to electrostatic discharge, as well as exhaustive specifications and measurements of performance. There’s even a break down of the optical package, too, including a patent search to shed more light on the complicated inner workings of the hardware.
And if this lures you to dig deeper into Sam’s Laser FAQ, prepare to spend the rest of the week.
We’ve seen other optical teardowns before, too – like this look inside a stereo microscope. It’s quite technical stuff, and may fly over the heads over the optically inexperienced. However, for those in the know, it’s a great look at the technology used in a mass-produced console.
There’s a whole lot of interesting mechanics, optics, and electronics inside a Blu-ray drive, and [scanlime] a.k.a. [Micah Scott] thinks those bits can be reused for some interesting project. [Micah] is reverse engineering one of these drives, with the goal of turning it into a source of cheap, open source holograms and laser installations – something these devices were never meant to do. This means reverse engineering the 3 CPUs inside an external Blu-ray drive, making sense of the firmware, and making this drive do whatever [Micah] wants.
When the idea of reverse engineering a Blu-ray drive struck [Micah], she hopped on Amazon and found the most popular drive out there. It turns out, this is an excellent drive to reverse engineer – there are multiple firmware updates for this drive, an excellent source for the raw data that would be required to reverse engineer it.
[Micah]’s first effort to reverse engineer the drive seems a little bit odd; she turned the firmware image into a black and white graphic. Figuring out exactly what’s happening in the firmware with that is a fool’s errand, but by looking at the pure black and pure white parts of the graphic, [Micah] was able guess where the bootloader was, and how the firmware image is segmented. In other parts of the code, [Micah] saw thing vertical lines she recognized as ARM code. In another section, thin horizontal black bands revealed code for an 8051. These lines are only a product of how each architecture accesses code, and really only something [Micah] recognizes from doing this a few times before.
The current state of the project is a backdoor that is able to upload new firmware to the drive. It’s in no way a complete project; only the memory for the ARM processor is running new code, and [Micah] still has no idea what’s going on inside some of the other chips. Still, it’s a start, and the beginning of an open source firmware for a Blu-ray drive.
While [Micah] want’s to use these Blu-ray drives for laser graffiti, there are a number of other slightly more useful reasons for the build. With a DVD drive, you can hold a red blood cell in suspension, or use the laser inside to make graphene. Video below.
Continue reading “Reverse Engineering A Blu-ray Drive For Laser Graffiti”
[Nav] got the bug for a tiny little laser cutter. He pulled off the build, and has just finished the second rendition which makes some nice improvements. He’s was hoping for a laser cutter, but we think this really shines when it comes to branding objects like the scrap wood seen above.
This joins a long line of optical drive parts builds. For instance, we saw this plotter that used the lens sleds from some CD-ROM drives. You may think that [Nav] doesn’t need to worry about the Z axis since this is a laser but you’d be wrong. The focal point of the light needs to hit at the right place to cut efficiently, and this is often the trouble with laser cutters. As material is burned away the laser becomes less efficient if you don’t adjust the lens for vertical position. That’s why we think it’s best as an engraver, but the original build writeup for his cutter does show some success cutting letters in dark paper.
Check out a clip of this design being burnt into the wood after the break.
Continue reading “Blu-ray CNC Looks Great For Branding And Engraving”
[Luigi Auriemma] almost rendered his brother’s TV useless attempting to play a simple practical joke. In the process, he uncovered a bug that could potentially upset a lot of people. His idea was to connect a computer to the system via WiFi, masquerading as a remote control. [Luigi] found that by altering the packet being sent to the TV by adding a line feed and some other characters to the name, it would begin an endless reboot loop.
He also discovered that he could easily crash the devices by setting the MAC address string too long. We’re not sure if he’s modifying the remote, or the television on this one though.
These bugs affect the Samsung TVs and Blu Ray players that utilize the same chip. The crazy part is that despite his attempts, he has been unable to contact anyone at Samsung to let them know!
We can think of no better way to describe this laser projector project than Epic. [C4r0] is a student at Gdansk University of Technology and he’s been working on this projector for at least a couple of years. It uses several different laser diodes pulled out of DVD burners, Blu-Ray drives, and entertainment equipment (the green diode is from a disco laser).
In order to direct the beams he built a series of brackets that hold dichroic filters which reflect some wavelengths of light while allowing others to pass straight through. Each diode also needs a driver, most of which he built from scratch. And once the hardware has been designed and tested, what does one do with it? If you’re [C4r0] you build it into a money case with professional-looking results.
Don’t miss the video demo after the break. And make sure you have a rag ready to wipe up the drool before you look at his forum post linked above.
Continue reading “RGB Laser Projector Is A Jaw-dropping Build”