LG 55LV770S (CHASSIS:LD12D) Service Manual ▷ View online
B. Power error
No power
Power LED
On?
Y
N
DC Power on
by pressing Power Key
On Remote control
by pressing Power Key
On Remote control
Y
N
Normal
operation?
Check Power
On ‘”High”
On ‘”High”
Check Power cord
was inserted properly
was inserted properly
Check
Power LED
Power LED
Replace
Power
B/D
Power
B/D
Measure voltage of each output of Power B/D
N
Y
Normal
voltage?
Replace Main B/D
N
Y
OK?
Replace Main B/D
N
Y
Normal?
Check ST-BY 3.5V
Replace Power B/D
N
Y
Normal
voltage?
Replace Power
B/D
B/D
Y
☞A17
☞A18
☞A19
☞A4
Standard Repair Process
Established
date
date
Revised date
7/14
LCD TV
Error
symptom
symptom
7
. Stand-By: Red
. Operating: white
. Operating: white
Close
2010.12.14
B. Power error
Off when on, off while viewing, power auto on/off
Error?
N
Y
Check Power Off
Mode
Mode
Fix A/C cord &
Outlet and check
each 3 phase out
Outlet and check
each 3 phase out
Check A/C cord
Check for all 3- phase
power out
Check outlet
Replace Main B/D
CPU
Abnormal
(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?
Replace Power B/D
Replace Power B/D
N
Y
Normal?
End
※ Caution
Check and fix exterior
of Power B/D Part
of Power B/D Part
☞A22
☞A19
Established
date
date
Revised date
8/14
LCD TV
Error
symptom
symptom
Standard Repair Process
8
Status
Power off List
Explanation
Normal
"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"
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"
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
* Please refer to the all cases which
can be displayed on power off mode.
Abnormal
1
2010.12.14
No audio
Screen normal
Screen normal
Check user
menu >
Speaker off
menu >
Speaker off
Off
N
Y
Cancel OFF
Check audio B+
24V of Power
Board
24V of Power
Board
Normal
voltage
Y
N
Replace Power Board and repair parts
Check
Speaker
disconnectio
n
Speaker
disconnectio
n
N
Y
Replace Speaker
Replace MAIN
Board
Board
End
C. Audio error
No audio/ Normal video
☞A24
☞A25
Disconnection
Established
date
date
Revised date
9/14
LCD TV
Error
symptom
symptom
Standard Repair Process
9
2010.12.14
→ abnormal audio/discontinuation/noise is same after “Check input signal” compared to No audio
C. Audio error
Wrecked audio/ discontinuation/noise
Wrecked audio
/Discontinuation
/Noise for all
audio
Check and
replace speaker
and connector
replace speaker
and connector
Wrecked audio
/Discontinuation/
Noise only
for D-TV
Wrecked audio/
Discontinuation/
Noise only
for Analog
Wrecked audio/
Discontinuation/
Noise only for
External Input
Connect and
check other
external device
check other
external device
N
Y
Normal
audio?
Check and fix external device
Replace Power B/D
N
Y
Normal
voltage?
Check input
signal
-RF
-External
Input signal
signal
-RF
-External
Input signal
Signal
normal?
(When RF signal is not
received)
Request repair to
external cable/ANT
provider
received)
Request repair to
external cable/ANT
provider
Y
Check audio
B+ Voltage (24V)
B+ Voltage (24V)
Replace Main B/D
(In case of
External Input
signal error)
Check and fix
external device
External Input
signal error)
Check and fix
external device
Replace Main B/D
N
End
Established
date
date
Revised date
10/14
LCD TV
Error
symptom
symptom
Standard Repair Process
☞A25
10
2010.12.14
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