AD FAA-2012-0987

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-300, 737-400, 737-500, and 757-200 series airplanes. This AD was prompted by a report of damage caused by electrical arcing to the wires that connect seat electronics boxes (SEBs). This AD requires installing a new relay and doing certain wiring changes of the entertainment control switch. We are issuing this AD to prevent power from being supplied to passenger seats when the entertainment control switch is in the OFF position, which could cause an electrical shock hazard resulting in serious or fatal injury to maintenance personnel.