Some weeks ago I suggested a scenario which might explain the loss of this aircraft, but I note that every single one of my posts has been deleted. I don't have time to present the case in detail again, but in summary:
B777 has a history of MEC fires dues to GB & BTB contactor failures
There is no smoke detection warning, fire detection or suppression in the MEC
In event of fire the smoke is vented overboard, so a fire can take hold unnoticed.
Damage progresses to structure and wiring.
At TOC, acars and vhf failure due damage is followed by dual fmc failure.
Crew divert to WMKP, only lat/long waypoints can be used in alternate nav.
Failure progresses :smoke in cabin, slow depressurisation unnoticed (no aural warnings-see AAIB reports) crew incapacitation. Fire out due low O2 partial pressure.
A/C navigates in LNav to alt nav waypoints, last two erroneously entered and unchecked.
My final post was to raise the possiblity that the last point latitude (WMKP) might have, under pressure, been entered as 5S, or 50S instead of 5N and that the a/c may gave been navigating to 5S100E or 50S100E.
I suggested that the search should perhaps be along the 100E meridan, but at the time this was well east of where the search was being conducted. This latest news of the ping pickup at S25101E, if it checks out as the MH370 FDR, does lend some credence to the possiblity of an MEC fire as the original cause of the disappearance.