Daewoo 103FH, Service Manual

Page: 18 / 58

16
TROUBLESHOOTING HINTS
1. No Character
Are the
Contrast &
Brightness Controls
maximum?
Change the Contrast &
Brightness control value to
maximum
No Raster
Refer to
No Raster
Check the peripheral circuit
of CRT
Check the video output
circuit and IC803 (pin 4, 6, 14)
and their ambient circuit
Trouble in 12Vdc line
of the Main PWA
Check the clamping pulse
circuit
Check the signal cable
No Character
Is whole
screen bright?
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Yes
Yes
Rk, Gk, Bk
About 45Vpp
No
No
Is CRT
Cathode (Rk, Gk, Bk)
signal level
normal?
Is the
output signal of the
pin 29, 32, 35 pre-amp
(IC802, M52742ASP)
normal?
Is clamping
pulse (pin 19 of IC802)
normal?
Is 12Vdc line
normal?
Is input signal
normal?
Trouble in IC802 and
its ambient circuit