Samsung RF265AB, Service Manual, Page: 63 / 107

64
TROUBLESHOOTING
4-2-5. If Power is not supplied
Caution
At the power of main PCB, the
AC115(220)V power and a high-
voltage over DC 170(325)V are
occurred. Please take care of
yourself on repair and measurement.
Check in SMPS PBA
Start
- Refer to function and
reference parts in the manual
when check the MAIN PCB
Connect plug again,
check the plug loosening
Check the assembly and wire
connection
1) Replace FUSE AC 250V 2.0A
2) Replace SMPS assembly
Replace PCB ASS'Y
1) Replace U4 (D10LC20U)
2) Replace PCB ASS'Y
1) Replace REG1 (KA7805)
2) Replace PCB ASS'Y
1) Check assembly wire and repair
2) Replace Panel PCB
1) Solder again
2) Replace PCB MAIN
- Check MAIN PCB connection
- Check the connections
between cabinet to door
- Check the connections
between door to panel PCB
1) Check the contact of lead wire
2) Replace the applicable relay / PCB MAIN
1) Check PCB PATTERN and replace BD1
2) Replace PCB ASS'Y
Is plug connected in?
Is power 115(220)V
both terminals of SMPS
PCB CN1?
Is fuse on the SMPS
PCB down?
Is DC170(325)V applied
between both
terminals of BD1+,-
Is DC5.8V
applied between TOP
switch 246Y C to S?
Is 12V applied between
both
terminals of C16?
Is 5V applied between
both
terminals of C19?
Does Panel PCB
operate normally?
Is normal load such
as Relay?
Is there any PCB
soldering, short,
breakage?
Normal(Recheck)
Checking method of SMPS voltage CN1
input ; CN1#1(Red) #3(Black) AC voltage
Checking method of SMPS 2nd output
voltage CN2 input ; CN2#1(Red)
#3(Black) same as C19 terminals..
DC 5V 0.3V
Checking method of SMPS 2nd output
voltage CN2 input ; CN2#5(Yellow)
#3(Black) same as C16 terminals.
DC 12V 0.6V