GE JS998 Series - Fan and Motor Failures Troubleshooting; Convection Fan Not Working Troubleshooting

– 52 –
Convection Fan Does Not Work
No
Disconnect the convection fan.
Is 120 VAC present from the MPB relay
K105 NC or NO contact to AC IN (NT)?
Yes
No No
Yes
Enter the service mode and
turn the convection fan on.
Is the convection fan on?
No
Is 120 VAC present from
the convection fan positive connectors to AC IN (NT)?
Yes
Replace the EMI filter
board or repair the
faulty ground wire.
No
Is 120 VAC present from the
MPB relay K105 COM
contact to AC IN (NT)?
Is 0 or 12 VDC present
from the MLB connectors
J1, pin 16 to J3, pin 2?
Is 0 or 12 VDC present
from the MLB connectors
J3, pin 16 to J5, pin 2?
Repair the faulty
wiring from the MLB
to the MPB.
Replace
the MLB.
Yes
No
Replace
the MPB
Is 120 VAC present from
the MPB relay K4 NO
contact to AC IN (NT)?
Yes
Repair the faulty
wiring from MPB
relay K105 to K4 .
Is 120 VAC present from
the MPB relay K4 COM
contact to AC IN (NT)?
No
Yes
Replace the EMI
filter board or repair
the faulty wire.
Is 0 VDC present from
the MLB connectors J3,
pin 15 to J5, pin 2?
No
Yes
Replace
the MPB.
Replace
the MLB.
Yes
Replace the
convection fan.
Yes
Is 0 VDC present from
the MPB connectors
J1, pin 15 to J3, pin 2?
No
Yes
No
Repair the faulty
wiring from the
MLB to the MPB.
Repair the faulty wire
from MPB relay K105
NO or NC contact to
the convection fan.
Is 120 VAC present from
the convection fan positive
and negative connectors?
No