Drivers on the Massachusetts Turnpike heading into Boston likely are familiar with the 30-foot-by-45-foot LED digital screen, part of the highway-facing façade of WGBH's studio complex in Brighton, Mass. Since the new building and its dynamic exterior's debut in September 2007, the screen features an image or series of images drawn from the day's television or radio programming, or from other sources that reflect the station's mission. Images are projected onto the screen every day from 6:30 a.m. to 7 p.m. At night, an image of the evening sky over Boston is displayed. But the screen, despite its engaging content, was turned off in mid-July 2008 because of technical issues. At just a year old, it was discovered that some of the LEDs producing the images would go dark when they became too warm, which led WGBH to shut down the digital screen until September 2008 to install an enhanced cooling system to keep the LEDs from overheating.