Daewoo 712B Service Manual page 18

2. No Raster
heater red-hot?
Turn the Brightness
& Contrast control
to set Maximum
screen bright?
G1 voltage about
G2 (screen) voltage
turning the Brightness
control counterclockwise
Trouble in FBT
No Raster
Is CRT No
Yes
Yes
Is whole
Yes
Check
-30V?
Yes
Is CRT
about 500V?
Yes
Is 80Vdc
line normal?
Yes
Does
make screen
bright?
Yes
Is Heater
Voltage (CRT PWB)
about 6V?
Yes
Trouble in
power supply
circuit
No
Trouble in power
supply circuit
No
Trouble in G1
line of Main PWB
No
Trouble in FBT
Trouble in 80Vdc
No
line of power
supply unit
No
High Voltage
trouble in FBT
16
No
Trouble in
CRT
Refer to trouble in
power supply unit.
Refer to trouble
in P.S.U