We've seen our share of hardware failures over the years, but we can't find any direct precedent for this. The Raspberry Pi 2 has been available for a few days, and naturally many enthusiasts started taking photos of their devices. However, a member of the official forum discovered that if you capture an image of the Raspberry Pi 2 using a Xenon flash from less than fifty centimeters… the computer hangs. What's going on?
A Strange Discovery
The game Cosmic Ark developed for the Atari 2600 console has a very special place in video game history. Developers not only had to make the most of every available byte back then, but also bend some rules when possible. In the specific case of Cosmic Ark, the starry background sky was caused by a bug in the hardware. 33 years later, hardware bugs maintain their negative profile, causing delays in production lines and other harmful effects once the product hits the market, but there is always room for curious and unexpected effects. The latest example comes from the brand new Raspberry Pi 2. The new computer received notable improvements in its specifications, and support for Windows 10 has excited many people… although it carries a small detail: it doesn't like photos.
The Culprit: U16
In reality, it doesn't like photos taken using a Xenon flash. All those who use cameras and/or smartphones with LED flashes will see that the Raspberry Pi 2 is much more willing to be photographed, but a relatively close shot (50 centimeters or less) with a Xenon flash causes the new Raspberry Pi to freeze. Its red light turns on, the screen becomes static, and it responds to no command. Removing the power source and reconnecting it is all it takes to bring the Raspberry Pi 2 back from the darkness; however, enthusiasts quickly detected the cause. Apparently, the chip called “U16” linked to the Pi's power section is a bit more photosensitive than normal, and the Xenon flash merely induces a remote reset. A clear example of the photoelectric effect.
A Simple Fix
Some users have reproduced the effect using laser pointers to illuminate U16, which also speaks of a minimum level of light concentration. How to fix it? Easy: covering the chip . Those in possession of dark cases only need to keep the Raspberry Pi 2 inside them, but those working with the exposed PCB can use some black electrical tape or putty, and alternatives such as black nail polish or a pinch of epoxy of the same color have also been suggested, without losing sight of its proximity to several capacitors and resistors. The Raspberry Pi 2 developers confirmed that the bug causes no permanent effects, but it is recommended not to abuse it.
