Text preview for : nokia__447ziplus_monitor_sm.pdf part of NOKIA nokia 447ziplus monitor sm NOKIA Monitor nokia__447ziplus_monitor_sm.pdf
Back to : nokia__447ziplus_monitor_ | Home
8. TROUBLESHOOTING FLOW CHART
(1) Power Start NG
Power start NG
Is the
No voltage at
C815 normal
(125-340V)
?
Is Yes
F801 Replace Yes
open ? F801
Does Yes
No R808
open?
Check power socket copper and
plug & D811...D814, R805
No
Check Q868,I862,D831,R867
Is the
No start-up
voltage at
C831(16V)
?
Check R849, R848, D870, C831,
D831, R831,Q850 Yes
Is the
voltage of Yes
R867 normal
(>1Vpp)?
No Check secondary side circuit.
D802~D807 or any short circuit
on B+ output,R867 resistance
Q820,Q821,Q822,
Q823 and their input
control logic
www.rtv-horvat-dj.hr
27
(2) No Video (raster appear)
No Video(raster appear)
Are the
No
waveforms at
pin 2,6,11 of
I901 Normal
?
Check signal cable,
C901, C931, C961
Yes
Are the
voltages at pin No
15 of I901
normal ?
Check ABL line from PCB
Yes
Are the
waveforms at
pin 35,32,29 of
I901 normal ? No
Is
The voltage at pin Yes
Yes 17 of I901
normal ?
Are the I901 is defective
waveforms at
No cathode R/G/B No
of CRT normal Check D941
?
Check video circuit
voltages on
Pin 1,3,5 of I904.
Yes
Check 12V lines
Check 75V lines. CRT is defective.
www.rtv-horvat-dj.hr
28
(3) No Raster appear
No raster appear
Is
the H.V. Yes
correct
?
Does raster
No
light up with Yes
SCREEN control
turned clockwise
Is the ?
voltage at O/P Reset SCREEN
No
of D442 normal No control.
(69...165V)? Is the
Check B+ converter
voltage at Yes
CKTQ440, Q438,
heater normal
Q439, D442 Yes (6.3V) ?
Check brightness
No circuit Q495,
Q497, R482
Check spot killer
Check R930, P902 Ckt Q348, D348
Is the
Check FBT, CRT
waveform at
Pin 1 of T430 No
normal ?
Is the
waveforms at
Yes Pin 26 of I401 Yes
normal ?
Open L440, Input 31KHz
Check Q429,
signal apply 80V DC on
D428, C427, R424
Pin 9 of T440 No
+14V to Q429
Check I401