So if this occurred, then it is pretty likely that some (or most) electronics would fail, with the equipment cooling set off, with the combination of a fire, and as the crew tries to vent the smoke, the fire spreads, and eventually leads to cabin depressurization, which ends up killing the crew... Plausible?
Part of the prior two smoke checklists that I didn't post advise the crew to 'plan to land at the nearest suitable airport' if the smoke/fire persists after carrying out the immediate items - turning off airconditioning packs (one at a time), APU off, recirc fans off, In flight entertainment off, cabin power off etc .
If not already on descent to a nearby airport and the pressurisation fails then the crew are already on their oxygen supply due to the smoke/fire. As this is unlikely to be an explosive depress then it isn't a huge drama, the crew will get an alarm of either airconditioning pack failure or cabin altitude climbing. They will then descend fairly quickly to the lowest safe altitude considering terrain or, as in this scenario, 10,000ft.
The crew oxygen supply (gaseous) is good for about 30 minutes. If the cabin climbs above 14,000ft then the pax oxy masks automatically deploy. I understand these are released from the overhead bin area via a barometric device and should not need elec power.
I believe MAS uses a gaseous ring main with ~15-20mins of pax oxy, but there is an customer option to fit the aircraft with chemical oxygen generators but these have less capacity.