FLASHBAKE
®
/ MICROWAVE OVEN TROUBLESHOOTING
Form 24694 (April 2001)
Page 47 of 52
TROUBLESHOOTING
DIAGNOSING NON OPERATING
UNIT
A non operating unit is better defined as a unit that
appears to have no power to it (no clock display,
cavity lamp or keypad responses). The following
components and associated wiring should be
checked in the order below when diagnosing a non
operating unit.
1.
Confirm power at the electrical outlet (120 volts
AC on each leg - L1 to Neutral and L2 to
Neutral).
2.
At the power cord head, use your volt/ohm
meter and check resistance from L1 to Neutral.
The resistance should be approximately 22
ohms. Note that this reading is shown in the
schematic diagram at the low voltage
transformer primary resistance.
3.
If you do not read continuity from L1 to Neutral,
suspect the following:
•
open fuse
•
open cavity thermal cut out (TCO)
•
low voltage transformer (open primary
winding)
•
open magnetron thermal cut out (TCO)
•
open thermal fuse
•
malfunctioning control board
•
check all associated wiring and wiring
connections
4.
If you read approximately 22 ohms from L1 to
Neutral suspect a malfunctioning control board,
loose wiring connection or open secondary
winding of the low voltage transformer.
