Trouble Shooting Guide - Panasonic NR-B420M Service Manual

B420M/MS/MW, B480M/MS/MW,
B570M/MS/MW/D/D-*9, B53D2,
B643M/MS/MW/D/D-*9, B703M/MS/MW,
C603D, C703M/MS/MW/D
SECTION I TROUBLE SHOOTING GUIDE
Symptom 1. No cooling at all.
Compressor does not operate.
Does light inside
refrigerator light up?
YES
Does compressor
operate when thermostat
is short circuited?
NO
Does compressor
operate when
timer is set to colling
operation side?
NO
(No compressor motor operation noise.)
NO
Power breaker OFF.
Power cord
disconnected.
Broken wire in
power cord.
Yes
Thermostat gas leak.
Faulty thermostat
contacts.
Yes
Blown temperature fuse
(Disconnect two joints of both ends of fuse
and check continuity between sky blue and
brown joint.)
Defrost heater broken
Faulty timer contacts
(Disconnect timer wires and check continuity between yellow
green (3) and gray (4) terminals of timer. Fig. 1)
Faulty overload
protector contacts
(Short circuit wires and of the overload protector; it the
compressor operates, the overload protector is faulty. Fig. 2)
Reset power
breaker.
Plug in power
cord.
Replace power
cord.
Rèplace
thermostat.
Replace
thermostat.
Replace bimetal
thermostat and
temperature fuse
Replace
defrost heater.
Replace timer
Replace
overload relay
---- 2 ----
Fig. 1
Continuity
check
Ohm meter
Fig. 2