Troubleshooting Hints - Daewoo 531X-3 Service Manual

6. Static Convergence Adjustment
(a) Apply a magenta cross hatch pattern on display.
(b) Adjust the focus from the best over all focus on the display.
Also adjust the brightness to the desired condition.
(c) Vertical red and blue lines are converged by varying the angle between the two tabs of the 4-pole
magnets.
(d) Horizontal red and blue lines are converged by varying the tabs together, keeping the angle between
them constant.
(e) Apply a yellow cross hatch pattern on display.
(f) Vertical green and red lines are converged by barying the angle between the two tabs of the 6-pole
magnets.
(g) Horizontal green and red lines are converged by varying the tabs together, keeping the angle
between them constant.
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TROUBLESHOOTING HINTS

1. No Character
No Character
Are the Contrast &
Brightness Controls in
OSD menu
maximum?
Yes
Is whole
screen bright?
Yes
Is CRT
Cathode (Rk, Gk, Bk)
signal level
normal?
No
Is the
output signal of the
(pin 19,20,21) pre-amp
IC801(LM1238) normal?
No
Is 5V line
normal?
Yes
Is blanking
pulse (pin 23 of IC801)
normal?
Yes
Is input signal
normal?
Yes
Trouble in IC801 and
its ambient circuit
Change the Contrast &
No
Brightness control value to
maximum
No
Refer to
No Raster
No Raster
Yes
Check the peripheral circuit
of CRT
Rk, Gk, Bk
About 30~35Vpp
Yes
Check the video output
circuit and its ambient circuit
No
Trouble in 5V line
of the Main PWA
No
Check the clamping pulse
circuit
No
Check the signal cable
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