How To Check Fault Symptom - Samsung UA42EH5000R Service Manual

4-2. How to Check Fault Symptom

No Power
„
• The PD board relay does not work when connecting the power cord.
Symptom
• The units appears to be dead.
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.
Major
checkpoints • Check the fuses of each part.
• Check the output voltage of PD.
• Replace the Main Board.
1
2
Diagnostics
3
4
Check 'Power of nand flash IC(A3.3V)' and
5
6
7
Power indicator LED on?
Yes
Check the backlight on, when 14p cable
unconnected ?
Yes
Check 'Stand-By 5V' DCA5V appear at?
BD216_L/BD210_S ?
Yes
Check 'SW_POWER Voltage' is under
0.5V at Q202 base ?
Yes
Check 'Power input of Main Ass'y' DC
B13V, B5V appear at?
BD219_L/BD213_S(B13V)
BD215_L/BD209_S(B5V)?
Yes
check 'Power of main IC(B1.2V, B2.5V)'
and check 'Power of DDR IC(B1.5V)'
appear at ?
TP_A3.3V/IC901(#1,2)
TP_B1.2V/BD1002 (B1.2V)
TP_B2.5V/BD1003/4/5/6 (B2.5V)
TP_B1.5V/BD1012 (B1.5V)
Yes
Check 'Power of LVDS (13V)' appear at
LVDS connector Pin #1~5?
TP-Panel_VCC
No Check an AC power connection.
No Change 14p power cable or SMPS.
No Change SMPS.
No Change Main Ass'y.
No Change SMPS.
No
Change Main Ass'y.
No
4. Troubleshooting
4-3