The Federal Aviation Authority FAA has told airlines to replace or modify the cockpit display units. These were apparently designed without consideration for Electromagnetic Compatibility (EMC)

US air safety regulator said that tests had indicated that mobile phone and computer signals could cause the screens to go blank. The affected planes are typically fitted with several screens, each of which costs thousands of pounds.

Honeywell - the displays' manufacturer - has stressed that the problem has not been experienced in-flight.

Full story - http://www.bbc.co.uk/news/technology-29445385

Wi-Fi interference with Honeywell avionics prompts Boeing action - http://www.flightglobal.com/news/articles/wi-fi-interference-with-honeywell-avionics-prompts-boeing-354179/