Samsung UE B7000WW Series, Service Manual

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4-8
4. Troubleshooting
4-1-1. No Power
Symptom
The PD board relay does not work when connecting the power cord.
The units appears to be dead.
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Major
checkpoints
The PD relay does not work when connecting the power cord if the cables are improperly connected or the
Main Board or PD is not functioning. In this case, check the following:
Check the internal cable connection status inside the unit.
Check the fuses of each part.
Check the output voltage of PD.
Replace the Main Board.
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Caution Make sure to disconnect the power before working on the IP board.
Diagnostics
Does proper Main DC B12VS,
B5V,B13V appear at the the PIN23,
PIN15, PIN9 of CN1001?
Does proper DC A3.3V appear at the
Pin5 of IC1002?
Change the IC1002 or the Main Assy
No
Yes
Does proper DC B3.3V appear at
1pin of IC1005 and IC1008, B9V
appear at 3pin of IC1003?
No
Yes
When power on, check the sound of
relay on?
Yes
No
Check a connection power cable.
P/N: BN96-09872A
Does proper Stand-By DC
A5V appear at the PIN 27 of CN1001?
No
Change the Main Power assembly
40” / 46” : BN44-00269A
55” : BN44-00271A
Yes
No
Yes
Change the IC1005, IC1008, IC1003
or the Main Assy
BN94-02706A
Does proper chelsea core 1.2V, 1.8V
appear at C1032, C1033?
No
Change the IC1007, IC1008
or the Main Assy
A power is supplied to panel appear
at C7136?
Check a other function (No picture part)
Replace a LCD Panel
40” : BN07-00700B
46” : BN07-00701B
55” : BN07-00702B
No
Yes