Nokia 447ZiPlus - R;G;B Signal Loss Diagnosis; Vertical Sync Loss Diagnosis

30
Is the
waveform at Pin
2/6/11 of I901
normal
?
Is the
waveform at Pin
29/32/35 of I901
normal
?
Is the
waveform at
cathode R/G/B of
CRT normal
?
R/G/B is Missing
Check signal cable.
C901/C931/C961
I901 is defective
Check video circuit
Waveform at pin
1/3/5 of I904
Check 12V lines
Check 79V lines
CRT is defective
(4) R/G/B is Missing
N
o
N
o
N
o
Yes
Yes
Yes
Is the
waveform at
Pin 32 of I501
normal ?
Is the
waveform at
Pin 40 of I501
normal ?
Loss of vertical
synchronization
Check
I401,C328
Check Q556 C328
Check I501
N
o
N
o
Yes
Yes
(5) Loss of Vertical Synchronization