LG 50PM4MA-WA (CHASSIS:PM75A) Service Manual ▷ View online
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3. No Raster
(1) Symptom
1) No OSD and image occur at screen.
2) It maintains the condition where the front LED is green.
2) It maintains the condition where the front LED is green.
(2) Procedure check
Check the PDP Module
Replace the
Power board.
Power board.
Does
minute discharge
at Module?
Is the inverter
/VaVs on?
Is output the normal
Low/High voltage except
for the Stand-by 5V?
Low/High voltage except
for the Stand-by 5V?
Yes
No
No
Is there a fault with
the link cable?
Yes
Is the output for the
IC800 normal?
Reconnect the link cable in
P803
P803
No
Replace the VSC.
No
Yes
Start Check
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4. In case of an unusual display in VIDEO(AV,S-VIDEO)
(1) Procedure check
Check the
input Jack(JK506,
JK514)
Check the Signal Cable
And Output Device
And Output Device
Yes
No
Check the
Video Switch IC Output
(CXA2040AQ)
Yes
Check A Block
Reconnect the link cable in
P803
P803
Change the IC(IC513)
No
1. Check the IC101
2. Check the Vcc of IC101
3. Check the Peripherals of
2. Check the Vcc of IC101
3. Check the Peripherals of
IC101
No Raster State
On Video Signal(AV/S-VHS)
Yes
Is the normal
video output of XA2040AQ?
(Check the R669, in case of
S-Video check R672,
R682)
Is the I2C communication
normal?
Is the Input voltage
normal?
No
Check the
Video Switch IC Output
(CXA2040AQ)
Check the power
Re-insert the Cable.
Change the IC(IC513)
No
No
No
No
YES
YES
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5. In case of an unusual display in RGB
(1) Procedure check
Check the
input Jack(P503)
Check the Signal Cable
And Output Device
And Output Device
Yes
No
Check the Schmitt triger
I/O SYNC(IC507)
Yes
Check the Vcc and
Peripherals of IC507
Peripherals of IC507
No
1. Check the IC101
2. Check the Vcc of IC101
3. Check the Peripherals of IC101
2. Check the Vcc of IC101
3. Check the Peripherals of IC101
No Raster State On
RGB Signal
6. In case of an unusual display in Component1,2
(1) Procedure check
Check the
input Jack(JK510,
JK511,JK512)
Check the Signal Cable
And Output Device
And Output Device
Yes
No
1. Check the IC101
2. Check the Vcc of IC101
3. Check the Peripherals of IC101
2. Check the Vcc of IC101
3. Check the Peripherals of IC101
No Raster State On
Component Signal
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15. HDMI mode
Is only video
normal?
Is only audio
normal?
No
Yes
Download EDID data each port.
Check the TMDS line wave.
(R312~E3273)
(R312~E3273)
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. (0x60, offset 0x06)
- Enable bit 6 : HDCP key loaded
- Enable bit 5 : HDCP decryption active
- Enable bit 4 : HDCP authentication attempted
- Enable bit 5 : HDCP decryption active
- Enable bit 4 : HDCP authentication attempted
Reset TMDS power down/ on register.
- 0x60, offset 0x3f : 0xf7 => 0xff
- 0x60, offset 0x3f : 0xf7 => 0xff
Check HDMI source.
Change to another source or cable.
Change to another source or cable.
Yes
Is the wave
continuous?
Normal video,
Normal audio?
No
Yes
Replace the IC508.
No
1. Unplug and plug in the HDMI cable.
(sometimes ESD surge occurred at HDMI port.)
2. Check the HDMI Mute register. (0x68, offset 0x37)
3. Check the Audio-out channel mute register (0x68,
3. Check the Audio-out channel mute register (0x68,
offset 0x32) is appropriately enabled.
Yes
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