[ChronicMA]

In past accidents the reasons it stops recording is:

1) loss of electrical power which is generated by the engines

2) disconnection of the wires that lead to the recorder.

So damage to the fuselage or to the power system are prime suspects.

[mabarker1]

3) Someone pulled the Circuit Breaker(s) but low probability of that in this case.

I'll lean towards the Bird Strike option causing damage to the wiring.

.PDF on Boeing 737-800 Electrical Systems.

Pages 4 & 5 on the .PDF Page Count are simple Schematics.

Looks like both engines have Generators and also the Aircraft has an APU (Auxiliary Power Unit) Generator as well. Automatic Power switching will switch to any of these systems if the needs arise.

[Chickensoup]

No battery backup?

Seriously?!