Acer A221HQV Service Manual page 56

ACER A211H/A221HQ
54
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5.3.8 Checking the resolution change IC movement:
Check +3.3V supply on I306 pin 51,
Check +1.2V supply on I306 pin 30,
Check X301 14.318MHz clock input to I306
Check I306 pin 54 RESET signal is
low level at normal operation.
Check I306 pin 21~24 SPI Flash
ROM interface signal.
Failure Point
I306 failure.
5. Troubleshooting (continued)
6
OK
53, 15.
OK
pin 1 and 2
OK
OK
OK
Proceed " Checking the DC/DC converter
NG
circuit" section.
Proceed " Checking the DC/DC converter
NG
circuit" section.
Failure Point
1) Printed wire broke between X301 and I306
NG
pin 26, 25.
2) C388, C389 is short or open.
3) X301 is failure.
Failure Point
1) Check I306 pin54 is from high to low level, it
is 3~10ms high level, when VCC5V is turned
on.
NG
2) Printed wire broke between I306 pin 54 and
C383/R337.
3) R337, C383 is short or open..
4) I306 failure.
Failure Point
NG 1) Printed wire broke between I306 pin 21~24
and I304.
2) I304 failure.