LG 37LG3000 / 37LG300C (CHASSIS:LD84A) Service Manual ▷ View online
- 21 -
TROUBLESHOOTING
TV/CATV doesn t display
Check TU500 Pin15(Video output),
Pin16(Sound output)
Can you see the normal signal?
Check the output of TR(Q503).
Can you see the normal waveform?
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
YES
NO
Could you measure voltage of
TU800 & IIC lines?
Are they all normal?
YES
NO
You should check power line
& IIC lines.
YES
You should replace TUNER.
NO
You should decide to replace TR(Q503)
or not.
NO
After checking the Power of Main
IC(IC100) you should decide to replace
Main IC or not.
This board has big problem because
Main IC(IC100) have some troubles.
After checking thoroughly all path once
again, You should decide to replace
Main Board or not.
- 22 -
DTV doesn t display
Check the output data of TU800
Pin 24~34
Can you see the normal signal?
NO
Could you measure voltage of
TU800 & IIC lines?
Are they all normal?
NO
You should check power line
& IIC lines.
YES
You should replace TUNER.
YES
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main
IC(IC100) you should decide to replace
Main IC or not.
This board has big problem because
Main IC(IC100) have some troubles.
After checking thoroughly all path once
again, You should decide to replace
Main Board or not.
- 23 -
AV1/2/3 doesn t display
Check J600,J600,JK607,JK618
Can you see the normal
waveform?
Check the input of Video
switch(IC700).
Can you see the normal waveform?
YES
NO
J600,J601 or SIDE AV may have
problem. Replace this Jack or SIDE
AV.
NO
After checking the Power of AV switch
you should decide to replace AV switch
or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main
IC(IC100) you should decide to replace
Main IC or not.
This board has big problem because
Main IC(IC100) have some troubles.
After checking thoroughly all path once
again, You should decide to replace
Main Board or not.
YES
- 24 -
Component doesn t display
Check J701.
Can you see the normal
waveform?
Check the input of Component
Audio switch(IC1001) ,
Can you see the normal waveform?
Check the output of Component
Audio switch(IC1001) ,
Can you see the normal waveform?
YES
YES
YES
NO
J701
may have problem. Replace this Jack.
NO
After checking the Power of component
Audio switch, you should decide to
replace component Audio switch or not.
NO
After checking the Power of component
Audio switch you should decide to
replace component Audio switch or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main
IC(IC100) you should decide to replace
Main IC or not.
This board has big problem because
Main IC(IC100) have some troubles.
After checking thoroughly all path once
again, You should decide to replace
Main Board or not.
Click on the first or last page to see other 37LG3000 / 37LG300C (CHASSIS:LD84A) service manuals if exist.