Shivaki STV-22LED3, Service Manual

Page: 49 / 57

SCART/PC/AV/ SCART/PC/AV/YPbPr YPbPr No Sound No Sound
5. Audio Trouble 5. Audio Troubleshooting
（ （
SCART/PC/AV/ SCART/PC/AV/YPbPr YPbPr No Sound No Sound
） ）
SCART/PC/AV/ SCART/PC/AV/YPbPr YPbPr No Sound No Sound
Check if other
channels are no sound?
Y
Reference to the
maintenance process
of “All Channels No All Channels No
Check if
U1_PIN194,196 have
audio signal?
N
N
Y
Check if the voltage
of U1_PIN197 is 3V
Check R384
Sound” Sound”
N
audio signal?
Check if the voltage of
U15_PIN16 is 5V?
N
Y N
Change C54
Check if the voltage
of C54 is 1.5V?
Check R139
N
Check if the control signal of
U15_PIN9,10 are normal
Y
Check U6_PIN93,128
Change U1
Y
Y
Check if the audio signal of
U15_PIN3,13 are normal
Check C239
、
C240
Y
Change the defective
components
Check if the input circuit from each
terminal to U15 is normal
Y
N
N
Change U15
Y
第 49 页，共 57 页