Panasonic NE-7920 Service Manual page 25

[TROUBLE 2] Oven does not operate at all; Display window does not dispaly any figures and any
inputs can not be accepted.
CONDITION CHECK RESULT CAUSE REMEDY
: 15A fuse Malfunction of
blows short switch
No
continuity
(Replace 15 A fuse}
Check continuity of Both Shorted contacts
both latch switch A's continuity of latch switch
contact and latch Aand B switch B. (secondary)
switch B's contacts and short switch
with door partially NOTE 1
open until short
switch contacts close
Replace latch switch
A(primary ), latch
switch B (secondary)
and short switch
Check continuity of
short switch with
door closed
Replace latch switch
A (primary), latch
Replace latch switch
A (primary) latch
switch B (secondary)
and short switch
and the other and incorrect
continuity
switch B
NOTE 1
Check continuity of Open or shorted Replace digital
primary winding of winding programmer
low voltage circuit
transformer
Refer to component yooh
test procedure on narnial
page 29. ( }
of the lead wire con- voltage capacitor
nected from trans-
former to the high
voltage capacitor 15A fuse Defective high Replace
and operate the unit again blows voltage transformer|
NOTE 1: All these switches must be replaced at the same time, please refer to pages 19 and 20 for adjustment
instructions.
Outlet has Check continuity of
No Defective
proper voltage. thermal cutout ees Peplace
Fuse does not (magnetron) CONTINUITY. thermal cutout
open
Check continuity of ;
No Defective
thermal cutout +e Replace
loven} continuity thermal cutout
Check continuity No Open power ee
of power supply continuity supply cord erlae
cord
Defective digital
programmer Repiace
circuit
B11