LG 84LA980T-DC (CHASSIS:LT34E) Service Manual ▷ View online
B. Power error
Off when on off while viewing power auto on/off
Established
date
Revised date
7/16
LCD TV
Error
symptom
Standard Repair Process
2013.01.31
Off when on, off while viewing, power auto on/off
Check outlet
☞
A19
Revised date
7/16
Error?
N
Check Power Off
Mode
Mode
Check A/C cord
Check for all 3- phase
Replace Main B/D
CPU
Abnormal
N
Y
Normal?
End
Y
Fix A/C cord & Outlet
and check each 3
and check each 3
Check for all 3- phase
power out
(If Power Off mode
Replace Power B/D
☞
A18
Abnormal
1
phase out
(If Power Off mode
is not displayed)
Check Power B/D
voltage
is not displayed)
Check Power B/D
voltage
Y
N
Replace Main B/D
Normal
voltage?
※
Caution
Ch k
d fi
i
Replace Power B/D
Check and fix exterior
of Power B/D Part
of Power B/D Part
Status
Power off List
Explanation
"POWEROFF REMOTEKEY"
P
ff b REMOTE CONTROL
* Please refer to the all cases which
N
l
"POWEROFF_REMOTEKEY"
Power off by REMOTE CONTROL
"POWEROFF_OFFTIMER"
Power off by OFF TIMER
"POWEROFF_SLEEPTIMER"
Power off by SLEEP TIMER
"POWEROFF_INSTOP"
Power off by INSTOP KEY
"POWEROFF_AUTOOFF"
Power off by AUTO OFF
"POWEROFF ONTIMER"
P
ff b ON TIMER
can be displayed on power off mode.
Normal
"POWEROFF_ONTIMER"
Power off by ON TIMER
"POWEROFF_RS232C"
Power off by RS232C
"POWEROFF_RESREC"
Power off by Reservated Record
"POWEROFF_RECEND"
Power off by End of Recording
"POWEROFF_SWDOWN"
Power off by S/W Download
"POWEROFF UNKNOWN"
P
ff b
k
t t
t li t d
7
"POWEROFF_UNKNOWN"
Power off by unknown status except listed case
Abnormal
"POWEROFF_ABNORMAL1"
Power off by abnormal status except CPU trouble
"POWEROFF_CPUABNORMAL"
Power off by CPU Abnormal
C. Audio error
No audio/ Normal video
Established
date
Revised date
8/16
LCD TV
Error
symptom
Standard Repair Process
2013.01.31
No audio/ Normal video
Revised date
8/16
No audio
Screen normal
Screen normal
Check user
menu >
Speaker off
menu >
Speaker off
Off
N
Check audio B+
24V of Power
Board
24V of Power
Board
Normal
voltage
voltage
Y
☞
A20
☞
A21+A18
Speaker off
Y
Cancel OFF
Board
N
Replace Power Board and repair parts
Check
Speaker
Speaker
N
Replace MAIN Board
End
Disconnection
disconnection
Y
Replace Speaker
8
C. Audio error
Wrecked audio/ discontinuation/noise
Established
date
Revised date
9/16
LCD TV
Error
symptom
Standard Repair Process
2013.01.31
→ abnormal audio/discontinuation/noise is same after “Check input signal” compared to No audio
Wrecked audio/ discontinuation/noise
Revised date
9/16
☞
A21+A18
Wrecked audio/
Discontinuation/
Noise for
all audio
Check and replace
speaker and
connector
speaker and
connector
Y
Check input
signal
-RF
signal
-RF
Signal
Y
Check audio
B+ Voltage (24V)
B+ Voltage (24V)
☞
A21+A18
Wrecked audio/
Discontinuation/
Noise only
for D-TV
N
Normal
voltage?
-RF
-External Input
signal
-External Input
signal
normal?
Replace Main B/D
N
Wrecked audio/
Discontinuation/
Noise only
for Analog
Replace Power B/D
(When RF signal is not
received)
received)
Wrecked audio/
Discontinuation/
Noise only
for External Input
Connect and check
N
Normal
received)
Request repair to external
cable/ANT provider
Request repair to external
cable/ANT provider
Replace Main B/D
(In case of
End
Connect and check
other external
device
other external
device
Y
Normal
audio?
Check and fix external device
External Input
signal error)
Check and fix
external device
signal error)
Check and fix
external device
Check and fix external device
9
D. Function error
Remote control & Local switch checking
Standard Repair Process
Established
date
Revised date
10/16
LCD TV
Error
symptom
2013.01.31
Remote control & Local switch checking
1. Remote control(R/C) operating error
☞
A22
☞
A22
Replace
Main B/D
☞
A22
Revised date
10/16
Y
N
Check R/C itself
Operation
Normal
operating?
Y
Check & Repair
Cable connection
Connector solder
Connector solder
Normal
operating?
Check B+
3.5V
On Main B/D
Normal
Voltage?
N
☞
A18
Check IR
Output signal
Normal
Signal?
N
Y
N
A22
Y
Check R/C Operating
When turn off light
in room
Check & Replace
Baterry of R/C
Close
Check 3.5v on Power B/D
Replace Power B/D or
Replace Main B/D
(Power B/D don’t have problem)
☞
A18
Repair/Replace
IR B/D
Normal
operating?
Close
If R/C operate,
Explain the customer
cause is interference
from light in room.
N
Y
Replace R/C
10
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