Troubleshooting Hints - Daewoo 719B Service Manual

TROUBLESHOOTING HINTS

1. No Character
Cathode (Rk, Gk, Bk)
(pin 16,18,20) pre-amp
pulse (pin 20 of IC801)
Trouble in IC801 and
No Character
Are the
Contrast &
Brightness Controls
maximum
Yes
Is whole
screen bright?
Yes
Is CRT
signal level
normal?
No
Is the
output signal of the
(IC801, TDA9210)
normal?
No
Is 6.3Vdc line
normal?
Yes
Is blanking
normal?
Yes
Is input signal
normal?
Yes
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 40Vpp
Check the video output
Yes
(IC802, TDA9536) and
their ambient circuit
No
Trouble in 6.3Vdc line
of the Main PWB
No
Check the blanking pulse
circuit
No
Check the signal cable
17
Refer to
No Raster