LG 42PT81 Service Manual page 25

19. HDMI mode
Is only video
normal?
No
Is only audio
normal?
Check the TMDS line wave.
(R1215~R1222 / R1226~R1233)
Is the wave
continuous?
Yes
1. Check the HDMI receiver's status register. (0x60, offset 0x06)
- If the value is 0xf or 0x8, it is normal.
2. Check the HDCP register. (0x6, offset 0x32)
- Enable bit 6 : HDCP key loaded
- Enable bit 5 : HDCP decryption active
- Enable bit 4 : HDCP authentication attempted
Reset TMDS power down/ on register.
- 0x60, offset 0x3f : 0xf7 => 0xff
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Only for training and service purposes
Yes
Download EDID data each port.
1. Check TV input mode.
Yes
(HDMI 1 port support HDMI and DVI.
So if you input DVI signal and PC audio from
phone jack, You can hear PC audio.)
2. Unplug and plug in the HDMI cable.
(sometimes ESD surge occurred at HDMI port.)
3. Check the HDMI Mute register. (0x68, offset 0x37)
4. Check the Audio-out channel mute register (0x68,
offset 0x32) is appropriately enabled.
No
Check HDMI source.
Change to another source or cable.
Yes
Normal video,
Normal audio?
- 25 -
No
Replace the IC1200.
LGE Internal Use Only