When The Product Is Not Powered On (98") - Samsung QB43R Service Manual

Troubleshooting

4-2-2. When the product is not powered on (98")

• The LEDs on The front panel do not work when connecting The power cord.
Symptom • The SMPS relay does not work when connecting The power cord.
• The units appears to be dead.
The IP relay or the LEDs on the front panel does not work when connecting the power cord if the cables
are improperly connected or the Main Board or SMPS is not functioning. In this case, check the following:
Main check
• Check the internal cable connection status inside the unit.
points
• Check the fuses of each part.
• Check the output voltage of SMPS.
Troubleshooting
guide
Precautions • Be sure to disconnect the power and start working.
4-8
Is the power on?
Yes
Is Backlight turned on when
the 30pin, 10pin cable does not
connected?
Yes
Is "Main power input voltage" normal?
Pin 22: B13V (CN202_L)
Pin 3: B13V (CN203_L)
Yes
Does A3.3V normally appear to BD239?
Does A1.8V normally appear to BD240?
Does A1.1V normally appear to BD241?
Yes
Does DC B3.3V normally appear to TP
B3.3?
Yes
Is the power applied to pin 6 of Q211 ?
Check power cable (power cord)
No
connections.
No
Change the 30pin cable,
if CN202_L is abnormal.
Change the 10pin cable,
if CN203_L is abnormal.
Change Assembly of main power.
No
Change IC202, If 1.8V is abnormal.
Change IC204, If 3.3V is abnormal.
No
Change IC206, If 1.1V is abnormal.
or Change Main Board.
No Change IC203 or Main Board.
Check the other functions.
No (No Display part)
Change the LCD panel.