Sanyo DP26649 Service Manual page 3

Repair Flow Chart: Trouble Condition
Green Power LED is on, but LCD backlights are not on.
Backlights are off, or only turn on and back off.
Power LED turns on.
But, LCD Backlight is not on.
On Main Bd.: On Main Bd.:
Are the 12V and 24V supplied from Are the 12V and 24V supplied from
Pwer Bd.? Pwer Bd.?
(see TABLE*1) (see TABLE*1)
yes
On Main Bd.:
Is the "BL_ON" voltage (3.3V)
supplied from Main Bd.?
(see TABLE*3)
yes: 3.3V
Confirm wire harness connection.
Especially between Power Bd. and
Inverter Bd.
Yes.
Inverter Bd. or LCD Panel is not working.
1st: Replace "Inverter Bd." (see note #1)
If Inverter Bd. does not correct problem, then:
2nd: Replace "LCD Panel"
(TABLE *1) Main Bd.: 12V & 24V Test Points
Model
US1J 26", 32"
US1K 42", 46"
Model
US1J 26", 32"
US1K 42", 46"
(TABLE *2) Main Bd.: "Power ON/OFF SW" Test Points
Model
US1J 26", 32"
US1K 42", 46"
(TABLE *3) Main Bd.: "BL_ON" Test Points
Model
US1J 26", 32"
US1K 42", 46"
(TABLE *4) Power Bd.: "24V" Test Points
Model
US1J 26", 32"
US1K 42", 46"
no: 0V
On Main Bd.
Is 5V supllied to "Power ON/OFF SW"
(see TABLE*2)
yes: 5V
Replace: "Power Bd."
and "Wire Harness"
no: 0V
Main Bd. is not working.
Replace "Main Bd."
12V on Main Bd.
Main K8B "8pin"
or
Main K8B "8pin" or
24V on Main Bd.
Main K8B "12pin"
or
Main K8B "12pin"
or
Power ON/OFF SW on Main Bd.
Main K8B "1pin" or
Main K8B "1pin" or
5V_STBY on Power Bd.
Main K8L "3pin"
or
Main K8L "3pin" or
5V_STBY on Power Bd.
Main K8L "3pin"
or
Main K8L "3pin"
or
Main Bd. is not working.
no: 0V
Replace "Main Bd."
note #1
If the model is
DP46849-00, DP46849-03, or DP46819-00 ,
please order the SMPS, in adition to the Inverter. These
versions have a HV Transformer that may not be working.
Change the SMPS first, if that does not fix the no BL
problem, then change the Inverter.
This note only applies to these three 46" units.
Main L1604
Main L1604
Main L1712
Main L1613
42"(00 ver) = 24V, 42"(01 ver) = 15V, 46" = 16V
Main R1702
Main R1600
Main R1754
Main R1829
Main R1754
Main R1829
Confirmation Voltage
12 V
12 V
Confirmation Voltage
24 V
Confirmation Voltage
5V
5V
Confirmation Voltage
3.3 V
3.3 V
Confirmation Voltage
3.3 V
3.3 V
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