phone problem

[jruizzle]

i have a lg optimus, when i try to make a phone call it just shuts down then repeatedly shows the "lg" symbol on and off, like when you go to turn it on. Ive tried rebooting the phone and it only seems to work for a while, if anybody has any guidance i would really appreciate it...

 

[Rukbat]

Put in a battery app, that records the battery voltage. After it shuts down, and you turnit back on, look at the graph. If the voltage took a dive to 0 just as the phone shut down, it's a bad battery. The added drain of making a call causes the voltage to drop, shutting the phone off.