TurboChef 2020 Service Manual page 56

3 6 T R O U B L E S H O OT I N G
Is wiring from the
control board to
the display
(including the
ribbon cable) OK?
Is 5 VDC present on pin 1 of
the J3 connector? (page 39)
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).
Does the keypad beep when a
YES
key is pressed?
Replace the fuses (page A-7).
NO
YES
NO
YES
Is the keypad cable properly connected
YES
to the control board?
Troubleshooting:
No Display - Screen is Blank
Correct wiring.
If cable is damaged,
replace it.
Replace the power
supply (page A-8).
Replace the I/O con-
trol board (page A-8).
Check wiring from the
power supply to the control
board. Correct wiring if
necessary (pages 37-40).
Troubleshooting:
No Keypad Input
NO
Is the 24 VDC power
NO
supply receiving
power?
YES
Is the power supply
NO
output 24 VDC?
YES
Is the control board
receiving correct VDC
(pages 37-40)?
NO YES
Verify 5 VDC is present
on pin 1 of the J3
connector (page 39). If
not, replace the control
board (page A-8).
NO
Correct wiring.