No Keypad Input - TurboChef 3240 Service Manual

Is wiring from the
control board to
the display
(including the rib-
bon cable) OK
(page 45)?
YES
Is 5 VDC present on pin 1 of
the J3 connector? (page 45)
YES
Replace the display and
ribbon cable.
(page A-8)
Replace the keypad (page A-8).
If the problem persists, or if beeps occur when
buttons are pressed but commands do not regis-
ter on the display, replace the control board
(page A-8).
Troubleshooting:
No Display - Screen is Blank
Does the keypad beep when a
YES
key is pressed?
Replace the fuses (page A-8).
Correct wiring.
If ribbon cable is
NO
damaged, replace the
keypad (page A-8).
Replace the power
supply (page A-8).
Replace the I/O con-
NO
trol board (page A-8).
Check wiring from the
power supply to the control
board. Correct wiring if
necessary (page 45).
Troubleshooting:

No Keypad Input

Is the keypad cable properly connected
YES
to the control board?
NO
Is the 24 VDC power
NO
supply receiving
power?
YES
Is the power supply
NO
output 24 VDC?
YES
Is the control board receiv-
ing correct VDC
(page 45-46)?
YES
Verify 5 VDC is present
on pin 1 of the J3
NO
connector (page 45). If
not, replace the control
board (page A-8).
NO
Correct wiring.
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