GEAppliances AZ75E09DAC, Technical Service Manual

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Dead Unit Troubleshooting
Check the ON/
OFF switch to be
sure it is on.
Is the thermostat
illuminated?
Check the fuse.
Fuse OK?
NO
Replace the fuse. NO
YES
Check for line
voltage between
terminals 3 and 7
at power cord
connector.
Voltage present?
Check for line
voltage on sub
board at CN204
between pins 5
and 7.
Voltage present?
NO
Check building
supply voltage and
power cord.
NO
Check for line
voltage between
driver board CN106-
1 and the brown
wire at RY202.
Voltage present?
YES
Check brown wire
between driver board
and RY202 (sub
board) for an open. If
OK, replace driver
board.
NO
Replace sub
board.
YES
Check for 24 VAC
at main board
CN3-1 to CN3-2.
Voltage present?
YES
Replace
transformer.
NO
Replace
thermostat.
YES
Check for 24 VAC at
main board terminal
strip (CN5) between
green fan wire (terminal
10 or 11) and common
wire (terminal 15).
Voltage present?
YES
Open green wire
or faulty
thermostat.
NO
Check for 10 VDC
at driver board
CN103-1 and
CN103-2.
Voltage present?
YES
Check for 10 VDC
at sub board
connector CN204-1
to CN204-2.
Voltage present?
NO
Open ON/OFF
switch or open
sub board.
YES
Replace
transformer.
NO
Check for 10 VDC
at driver board
CN107-1 to
CN107-3.
Voltage present?
YES
Replace sub
board.
YES
Check for 5 VDC
at main board
CN2-5 to CN2-10.
Voltage present?
NO
Replace driver
board
Replace main
board.
NO
YES