By Ray Thomas
Car ignitions that jam and result in accidents and deaths. Hoverboards with batteries that catch fire. Automotive safety airbags that explode and send shrapnel into faces and throats. Electronic vaporizers with batteries that explode in the smoker’s face. Endless other product failures. Making stuff is hard.
From amongst the endless stream of product failure reports, one particular manufacturing company’s problems with their Galaxy Note7 caught my attention. USA Today covered the gory details week after week as the Note7 story developed and as explosions in cars, homes, and hotel rooms were reported from Florida to Australia.
After weeks of reported problems, the U.S. Department of Transportation, Federal Aviation Administration, and Pipeline and Hazardous Materials Safety Administration issued an emergency order effective as of October 15 to ban all Galaxy Note7 smartphones from passenger airlines in the U.S. The Department of Transportation also banned the devices from shipping in air cargo. Then Amtrak banned Note7s from their trains. Railroads ship countless tons of extremely hazardous liquids and materials through cities and small towns throughout America so when they ban your consumer device from riding the rails, that’s adding insult to injury. Finally, after the maker of the Note7 saw a $20 billion drop in value because of the smartphones, they permanently stopped production of the devices.
How does it happen that a large corporation with decades of experience making a range of sophisticated products could suffer such an epic fail with their Galaxy Note7? Could something similar to the Note7 debacle happen to a cable operator? Possibly.
Cable operators purchase vast numbers of customer premises equipment (CPE) devices that go into customers’ homes to enable their subscribers to receive the services they are paying for. CPE devices have power supplies (PS) that convert 120 volts alternating current (AC) power at the electrical wall outlet to the direct current (DC) voltage(s) used by the CPE device. Sometimes the power supply is contained inside the CPE device (an internal PS). Sometimes the power supply is the small black plastic doohickey that plugs into the wall socket (an external PS). Either way, the majority of these types of power supplies are designed to safely fail by having at least one fuse. Some PS designs have two or three different ways to safely fail designed into the circuitry. But when homo sapiens are making decisions, they can be just like a house cat deciding to jump off a really slick surface and being captured on video for YouTube. Executive management has been known for epic fails in decision making over the centuries. Probably not a surprise that cats hold the lead over executives when it comes to deciding whether or not to jump.
Part of my work at two of the major MSOs was to observe quality acceptance testing at manufacturers’ test labs. Qualification testing generally lasted for one week and included a lengthy number of tests in a handful of categories. The manufacturers ranged from small outfits to the largest suppliers in the industry. All elements of product testing were important, but CPE power supply testing was especially critical because the devices were going in customers’ homes.
So what sort of things might testing reveal? A power supply might fail one of the different tests it was subjected to. The brown-out test is an example. Voltage is decreased in increments to simulate a power brown-out in a residential neighborhood. The behavior of the power supply is recorded and graphed to verify that it meets safety requirements. Either the PS passes or fails the test.
A more subtle thing is to ensure that qualification testing is properly structured. A possibility that quality testing must watch out for is if a manufacturer provides “prototype” units for testing that are not full production units. Many changes to a product can occur between prototype versions and full production. Perhaps this is what tripped up Samsung? Or perhaps it was something else. Because of my personal experience and interest in this area, I will continue to watch to learn the root cause of the problem behind the Note7 exploding in failure.
Owner, Kiama Tech, LLC
With more than 30 years in the cable industry, Ray is pursuing new challenges as an entrepreneur, consultant, and author. He is a member of the Society of Cable Telecommunications Engineers and the Institute of Electrical and Electronics Engineers, Inc.