Troubleshooting Hints - Daewoo 710C Service Manual

TROUBLESHOOTING HINTS

1. No Character
No Character
Are the
Contrast &
Brightness Controls
maximum?
Yes
Is whole
screen bright?
Yes
Is CRT
Cathode (Rk, Gk, Bk)
signal level
normal?
No
Is the
output signal of the
(pin 21, 24, 26) pre-amp
(IC801, KA2500)
normal?
No
Is 12Vdc line
normal?
Yes
Is clamping
pulse (pin 18 of IC801)
normal?
Yes
Is input signal
normal?
Yes
Trouble in IC801 and
its ambient circuit
Change the Contrast &
No
Brightness control to
maximum
No
No Raster
Yes
Check the peripheral circuit
of CRT Board
Rk, Gk, Bk
About 45Vpp
Check the video output
Yes
circuit and IC803 (pin 1, 3, 5)
and their ambient circuit
No
Trouble in 12Vdc line
of the Main PWB
No
Check the clamping pulse
circuit
No
Check the signal cable
15
Refer to
No Raster