Battery or Alternator problem?

[dr. d]

Thanks sa mga input sirs, so here's my story,

I jumpstarted my car and went to the nearest auto shop.
tinest nila yung batt and alternator, ok naman daw, may charge at nagcha-charge.
in-off ko engine(to show the problem is), then tried to start it again, hindi nag crank / redondo.
sabi ng electrician is starter na daw may sira, nilinisan and nagpalit lang ng carbon, ok na ulit. (P450 labor, P250 1set carbon)

funny thing is nung ginamitan ko ng ibang batt the first time hindi nag start, ok naman, kaya akala ko batt/alternator prob. Hays.

did the starter engage, i.e., did the starter solenoid function? this solenoid is more sensitive to low batt than the brushes...
sometimes, the solenoid gives warning signs before it completely bogs down..