Samsung RF4287HARS/XAC - If Power Is Not Supplied

85
TROUBLESHOOTING
4-2-7. If Power is not supplied
Caution
At the power of main PCB, the AC115V
power and a high-voltage over DC 170V
are occurred.Please take care of yourself
during repair and measurement.
Check in SMPS PBA
Start
- Refer to the 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 PCB ASS’Y
Replace PCB ASS'Y
Replace PCB ASS'Y
1) Check 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 and door
- Check the connections between
door and 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 the plug connected in?
Is power 115V applied
to the both terminals of SMPS
PCB CN70 ⑬-⑪
Is fuse on the SMPS
PCB down?
Is DC170V
applied to the both
terminals of BD1+,-
Is DC5.8V
applied between TOP
switch 246Y C and S?
Is 12V applied to the both
terminals of C107?
Is 5V applied to the both
terminals of TD102?
Does Panel PCB
operate normally?
Is the load (i.e. Relay)
normal?
Is there any
PCB soldering, short,
breakage?
Normal(Recheck)
☞ Checking method of voltage
CN70 - "11"(Red) ↔ "13"(Gray) AC voltage
☞ Checking method of DC 2nd output voltage
REG1 input ; Regulator 7805 → same as C107
terminals. DC 12.0V 0.8V
☞ Checking method of DC 2nd output voltage
REG1 output ; Regulator 7805 → same as
TD102terminals. DC 5V ± 0.5V
AW3 SM-EN 2011.3.31 2:56 PM 페 이 지 8 5 i n