Daewoo KOC-910K0P Service Manual page 28

(TROUBLE 6)
Lower heater is not heated; food will not become hot.
CONDITION
Lower heater
is not heated.
(TROUBLE 7)
The following visual conditions indicate a probable defective touch control Circuit or button P.C.B. assembly
1. Incomplete segments.
1) segment missing
2) partial segments missing
3) digit flickering other than normal fluorescent slight flickering
2. A distinct change in the brightness of one or more numbers exists in the
display
3. One or more digits in the display are not on when they should be.
4. Display does not count down or up with time cooking or clock operation.
5. Oven is programmable and cooks normally but no display shows.
6. Display obviously jumps in time while counting down.
7. Display counts down noticeably too fast while cooking.
8. Display does not show the time of day when clear button is touched.
9. Oven lamp and turn table motor do not stop although cooking is finished.
Check if the RELAY(RY4) contacts close and if they are close, replace touch control circuit.
CONDITION
Display does
Check each button for continu-
not show
programming
at all, even if
keyboard is
touched.
CHECK
Check continuity of
Primary interlock switch
Check continuity of
secondary interlock
switch
Check continuity of
heater
Check D.C voltage
Being supplied to
RELAY (RY7) coil
CHECK
ity of the button
RESULT
No
primary Interlock
continuity
No
continuity
No
Defective heater
continuity
0V
Faulty contacts of
Approx.
24V DC
RESULT
Normal
Malfunction of sub
27
CAUSE
Malfunction of
switch
Malfunction of
secondary
interlock switch
Defective
Touch control
circuit
RELAY
(RY7) or open
relay coil
CAUSE REMEDY
Replace sub
pcb assembly
pcb assembly
REMEDY
Adjust or
Replace
Adjust or
replace
Replace
Replace
Replace