How To Check Fault Symptom; 4-2-1.No Power And No Video - Samsung UA23H4003AR Service Manual

4. Troubleshooting

4-2. How to Check Fault Symptom

4-2-1.No Power and No Video

• 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:
• Check the internal cable connection status inside the unit.
Major
• Check the fuses of each part.
checkpoints
• Check the output voltage of SMPS.
• Replace the Main Board.
Diagnostics
4-4
Power cord on.
Yes
Check 'Stand-By A13V'
13V appear at BD207_NOFF/BN210_
OFF?
13V (CN201 #3/5/7/9)
-
Yes
Set On.
Yes
Check 'A_POWER'
Check 'A1.26V' appear at
1.26V (L203)
Check 'A3.3V' appear at
3.3V (IC201 #1)
Check 'A5V' appear at
5V (L202)
Yes
Check 'SW_POWER'
more than 3.3V appear at CN201(#2)
3.3V↑ (CN201 #6)
Yes
Check 'B_POWER'
Check 'B1.8V' appear at
1.8V (IC204 #5)
Check 'B3.3V' appear at
3.3V (IC205 #5)
Check 'B5V' appear at
5V (Q207 #1/2/5/6)
Yes
Cause : There did not supply the
power from SMPS.
No
Measure : Change 10p power cable
and SMPS.
Cause : There did not supply the
power from SMPS.
No
Measure : Change 10p power cable
and SMPS.
Cause : Main IC(IC1001) did not
control the SW_Power.
No
Measure : Change the Main Assy.
Cause : There is proble at DCDC/
LDO.
No
Measure : Change the Main Assy.