The electrical system of the Dreamliner is staggering in its complexity, as compared to earlier models. It uses six generators along with miniature "substations" to provide electrical power.
Its design relies a lot more on electrical componentry, and a lot less on pneumatics, with the design aim of reducing weight and increasing efficiency.
Even the hydraulics are electrically controlled on the Dreamline, a major design change from earlier Boeings.
However, I harbour a feeling that the investigators will find a cause for the thrust and power failures that will come from out of left field - a reason, that no-one, especially the Boeing designers and testers, ever imagined could happen.
Remember the FADEC blips on the Qantas Airbus that flew near the U.S. Navy communications base at Exmouth in 2008? The aircraft did an uncommanded descent of 650 feet before the crew intervened and corrected the flight path deviation.
It was found after extensive investigation, that the U.S. Navy low frequency radio wave generation overwhelmed the FADEC protection systems and more FADEC shielding had to be installed in the Airbus.
I'm wondering if some unexpected powerful radio signal generation in the Ahmedabad airport area, produced EMI interference with the Dreamliners electrical power systems?
GaryBPilot on YooTube points out an interesting thing about Flight 171 after takeoff. Everyone is trying to figure why the undercarriage didn't retract - which it should have, as soon as positive climb rate was established (normally only seconds after liftoff).
GaryBPilot outlines how the Dreamliner MLG bogies are electrically canted forward, prior to being retracted into the wheel wells. Conversely, the bogies are electrically canted backwards prior to landing.
This bogie canting process assists in improved undercarriage stowage when retracted, and assists in softer runway contact when landing.
Gary says he can see the undercarriage bogies commence their canting, which indicates the undercarriage retraction lever was selected. But then, the undercarriage goes no further in the retraction process. That would seemingly indicate a major power failure to the undercarriage retraction mechanism. This could be an indicator to further electrical failures that led to loss of thrust.
Another point is that India is the home of some pretty destructive critters, such as rats. If a rat got aboard undetected and chewed up important electrical componentry or wiring, and thus damaged redundancy features as well, that would go a long way to explain how "foolproof" aircraft systems could be damaged to the point where redundancy failed.
http://787updates.newairplane.com/787-Electrical-Systems/787-Electrical-System#