3. Unusual display from TV/CATV mode

Is video

output of the Tuner

normal?(CheckTU500

_Pin15)

Yes

Is the LVDS cable

connected well?

Yes

Change the IC(IC100).

No

Is the input

Yes

 

voltage normal?(Check

 

 

TU500_Pin4)

 

No

Check the Power.

No

Cable inserts well.

BLOCK A

Is the

Yes

I2C communication

Normal?(Check Pin10,

Pin11)

No

Check the Tuner.

Replace Main board.

4. Unusual display from DTV mode

Is video

No

Is the input

output of the tuner

normal?(Check TU500_

 

voltage normal?(Check

pin24~pin34)

 

Pin21,22)

 

Yes

 

 

No

 

 

 

 

 

 

 

Same as Block A.

 

Check the Power.

 

 

 

 

 

Yes

Is the I2C

Yes

 

communication Normal?

 

 

(Check Pin18,

 

 

Pin19)

 

No

Check the Tuner.

Replace Main board.

Copyright © 2008 LG Electronics. Inc. All right reserved.

- 16 -

LGE Internal Use Only

Only for training and service purposes

 

 

Page 16
Image 16
LG Electronics LD84A service manual Unusual display from TV/CATV mode, Unusual display from DTV mode