LG MH-1355M Service Manual page 32

CONDITION
No input can be programmed.
Some inputs can not be
programmed.
Display shows a number or
figure different from one
touched.
Random programming when
pressing other than touch
pads.
Display fixes some figure and
can not accept any input.
Setting time does not count
down when touch Start.
CAUSE
Defective membrane key of
P.C.B.
Loose connection.
Defective secondary switch or
out of adjustment
Defective membrane key of
P.C.B.
Loose connection.
– 32 –
TEST PROCEDURE OR
CORRECTION
Test procedure membrane key
of P.C.B. (See page 41.)
Connect them tightly.
Test procedure secondary
switch. (See page 25.)
Test procedure membrane key
of P.C.B. (See page 41.)
Test membrane key of P.C.B.