Front Switch Troubleshooting - Mitsubishi Electric LT-3280 Service Manual

4-2. Button switch is not effective. 4-2. Button switch is not effective. 4-2. Button switch is not effective. 4-2. Button switch is not effective. 4-2. Button switch is not effective.
Is the following harness connected correctly?
・
Between
CONTROL
(MC)
When it pushes the button switch, is the
signal
below available at pins 2, 3, of MC ?
3Vp-p only when switch is not pushed.
2, 3 :
Not 3V only when switch is pushed.
(It depends on switch)
IC700 (and peripheral circuits) are out of order.(PWB-MAIN)
MODELS: LT-3280D/LT-3780D
PWB-MAIN and
YES
YES
Page 43
NO
Poor harness connection or
defective cable.
PWB-
NO
Part on PWB-CONTROL is out
of order.