LG VX8500 Service Manual page 88

VX8500
Checking Flow
START
YES
Check Battery Voltage
> 3.4V ?
YES
Push power-on key and
check
the level change of
U301 PWR_ON
YES
Check the voltage of
the following port at U301
+1.4V_MSMC
+1.8V_MSMP1
+2.6V_MSMP2
+2.6V_MSMA
+2.8V_TCXO
YES
Logic level at
PS_HOLD(R301)
of U301=High ?
YES
Does it work properly?
YES
The Phone will power on.
LG Electronics Inc.
NO
Charge of Change Battery and try
NO
Check the contact of
NO
NO
Re-download software & try
NO
The power-on procedure is
completed.
The problem may be elsewhere.
96
again
power-key
Replace U301
again
Does it work
NO
properly?
YES
Replace the main
board.