Non-Fault Code Troubleshooting - No Display (Screen Is Blank) - TurboChef ngo Service Manual

40 TROUBLESHOOTING
Is wiring from the
control board to the
display OK?
YES
Is pin 1 on the J7
connector receiving 5
VDC? (see schematic,
page 45)
YES
Replace the display.
Troubleshooting:
No Display – Screen is Blank
Does the keypad beep when
YES
a key is pressed?
Replace the F1 and/or
the F2 fuse.
Correct wiring. If
NO
ribbon cable is
damaged, replace the
keypad.
Replace the power
supply.
Replace the control
NO
board.
Check wiring from the
power supply to the
control board. Correct
wiring if necessary.
NO
Is the power supply
receiving power?
NO
YES
Is the power supply
output 24 VDC?
NO
YES
Is the control board
receiving correct VDC?
NO
Verify voltage on pin 2
of the J7 connector is
24 VDC (see schematic,
page 45).
YES
Verify 5 VDC is
present on pin 1 of the
J7 connector. If not,
replace the control
board.