– 28 –
3. Check voltage between Smart Board CN103 pins
1 and 5 (18 VDC), pins 2 and 5 (12 VDC), pins 3
and 5 (12 VDC), pins 4 and 5 (5 VDC).
• If all voltages are correct, the Power Supply
is operating properly.
• If some but not all voltages are missing,
check wiring between the Power Supply
Board and the Smart Board. If wiring is OK,
replace the Power Supply Board.
• If all voltages are missing, go to step 4.
4. Check voltage between the double wire in the
connector that connects to Relay Board RY14
and the output of the Bottom TCO (yellow and
black wires).
• If 120 VAC is not present, see
Bottom TCO
,
troubleshooting step 3.
• If 120 VAC is present, check line and neutral
wiring to the Power Supply Board. If OK,
replace the Power Supply Board.
Disassembly
To remove the Power Supply Board:
1. Remove the Outer Cover. (See
Outer Cover
.)
2. Disconnect the 2 wire harnesses from the Power
Supply Board.
3. Remove the Phillips-head screw and ground
wire from the oven frame.
4. Remove the 2 Phillips-head screws that attach
the Power Supply Board to the Air Tunnel Inlet.
Disconnect
Disconnect
CN16
CN6
CN5
RY7
RY11
CN01
RY9
RY12
RY14
Relay Board
• Location
(See
Control Boards and Panel
Connections
.)
• Used for load switching, but also contains
voltage compensation circuits and the buzzer.
• Relays are switching neutral to loads.
• Heat source relays require:
◊
Relay Enable Voltage (5 VDC between CN01
pins 4 and 28.)
◊
Relay Operating Voltage (12 VDC between
CN01 pins 2 and 4.)
◊
Relay Activate Signal (5 VDC between
the active relay, see Relay Chart in
troubleshooting section), and CN01 pin 4.
Note:
Where applicable, board callout arrows
identify pin #1.
(
Continued Next Page
)