If Power Is Not Supplied - Samsung RF4287HARS Service Manual

AW3 SM-EN 2011.3.31 2:56 PM 페이지85 in
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
☞ 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
Is the plug connected in?
Is power 115V applied
to the both terminals of SMPS
PCB CN70 ⑬-⑪
Is fuse on the SMPS
applied to the both
terminals of BD1+,-
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)
PCB soldering, short,
- Check MAIN PCB connection
- Check the connections between
cabinet and door
- Check the connections between
Normal(Recheck)
door and panel PCB
Start
Connect plug again,
check the plug loosening
Check the assembly and wire
connection
PCB down?
1) Replace FUSE AC 250V 2.0A
2) Replace PCB ASS'Y
Is DC170V
1) Check PCB PATTERN and replace BD1
2) Replace PCB ASS'Y
Is DC5.8V
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
normal?
1) Check the contact of lead wire
2) Replace the applicable relay / PCB MAIN
Is there any
breakage?
1) Solder again
2) Replace PCB MAIN
85
- Refer to the function and
reference parts in the manual
when check the MAIN PCB