Nokia 447ZiPlus Service Manual page 32

(4) R/G/B is Missing
R/G/B is Missing
Is the
waveform at Pin
2/6/11 of I901
normal
?
Yes
Is the
waveform at Pin
29/32/35 of I901
normal
?
Yes
Is the
waveform at
cathode R/G/B of
CRT normal
?
Yes
CRT is defective
No
Check signal cable.
C901/C931/C961
No
I901 is defective
No
Check video circuit
Waveform at pin
1/3/5 of I904
Check 12V lines
Check 79V lines
(5) Loss of Vertical Synchronization
Loss of vertical
synchronization
Is the
waveform at
Pin 32 of I501
normal ?
No
Is the
waveform at
Pin 40 of I501
normal ?
Yes
Check I501
30
Yes
Check
I401,C328
No
Check Q556 C328