Panasonic NE-7920 Service Manual page 26

RESULT
CHECK
Check continuity of No
latch switch A continuity
Check continuity of No
latch switch B continuity
OV
CONDITION
Fan motor
and oven
lamp do not
turnon
Check D.C. voltage
being supplied to
power relay coil
(between terminal
7 and 8) with lead
wire connected to
relay coil terminals
Approx.
20 VD.C.
No
continuity
Check continuity of
primary winding or
digital programmer
circuit winding of high
voltage transformer
Fan motor
and oven lamp
turn on for
very moment
when the start
pad is tapped
Refer to component
test procedure on
page 28.
CAUSE REMEDY
Malfunction of
latch switch A
Malfunction. of
latch switch B
Defective digital
programmer
circuit
Adjust or replace
Adjust or replace
Replace
Faulty contacts
of power relay or
open relay coil
Open winding
Defective digital
programmer
circuit
Replace
Replace
Replace
CHECK
Check voltage being
supplied to variable
oscillation
power switch coil
Normal
NOTE 2
BE VERY CAUTIOUS OF HIGH VOLTAGE.
B12
REMEDY
CAUSE
Defective digital
transformer or Replace
faulty insulation
of filament
winding
Refer to component test
procedure on page 28
Shorted stack
diode
Replace
Refer to component test
procedure on page 28
Faulty variable
power switch
Refer to component test
procedure on page 29
Faulty magnetron
Ge to component test )
Replace
Repla ce
procedure on page 28