TROUBLESHOOTING HINTS

1. No Character

No Character

Are the Contrast &

No

Brightness Controls in

 

 

OSD menu

 

maximum?

 

 

Yes

 

 

 

 

 

 

Change the Contrast & Brightness control value to maximum

Is whole

 

 

 

 

 

 

 

 

 

No

No Raster

Refer to

screen bright?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No Raster

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is CRT

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

Check the peripheral circuit

Cathode (Rk, Gk, Bk)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

signal level

 

 

Rk, Gk, Bk

of CRT

 

normal?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

 

About 30~35Vpp

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is the

output signal of theYes (pin 14, 16, 18) pre-amp

IC801, normal?

 

No

 

 

 

No

Is 12V line

normal?

 

Check the video output circuit and its ambient circuit

Trouble in 12V line of the Main PWB

Yes

Is blanking pulse (pin 20 of IC801)

normal?

Yes

Is input signal

normal?

Yes

Trouble in IC801 and

its ambient circuit

No

5Vp-p

No

Check the clamping pulse circuit

Check the signal cable

15

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Daewoo 531X service manual Troubleshooting Hints, No Character