Acer NA23WABAS Service Manual page 42

5.2 Nothing display on screen (screen is black, color of LED is blue)continued
Continue
Check the 5V power supply for
P301 pin 4,5,6.
OK
Check the input voltage level whether was changed when
pressed function keys on the P308 pin1
OK
Check the P305 all LVDS signals.
NG
OK
Failure Point
1) The LVDS cable broke between P305
and LCD module.
2) LCD module is failure.
5. Troubleshooting (continued)
NG
Check the I301 pin2 if
NG
voltage is 3.3V
OK
Check the I305 pin2 if
NG
voltage is 1.2V
OK
Check the I307 pin2 if
NG
voltage is 5V
OK
Check if the voltage
between I307 pin2 and
pin3 is above -0.7V
NG
OK
Failure Point
I307 is failure.
Failure Point
1) Printed wire between R327 ,R331,
I307 pin1 is failure..
2) Q301 is failure.
NG
Check if the voltage on I312 pin 108 that is
Failure Point
I312 is failure
Failure Point
1) Printed wire broke between P305 and
I312 LVDS signals.
2) I312 is failure.
Proceed "Checking the DC/DC converter
circuit" section.
Proceed "Checking the DC/DC converter
circuit" section.
Failure Point
1) FB303 is open.
2) C316 is short.
Check if the Q301 pin2 of
PANEL_EN signal that
NG
outputted by I312 pin107 is
High level.
OK
from 3.3V to 0V.
NG
OK
ACER V233H
Go to cover page
Failure Point
1) Printer wire between R335
and I312 pin107 is failure
2) I312 is failure.
Failure Point
1) Printed wire broke between P308 pin 1
and I312 pin 108.
41