Fault diagnosis
2017-03-23 / DIS 184_58300000197442_ARA_EN_A
Copyright by BSH Hausgeräte GmbH
Page 36 of 101
4.3
Noise
Fault
Possible cause
Troubleshooting
Rails squeaking
(for appliances
without
a microwave)
Not a fault.
► Advise customer:
Slight squeaking is a normally occurring noise when sliding the rails in and out.
Ceramic rollers are jammed.
► Replace rail.
for appliances
with
a microwave
Telescopic bar is bent.
► Replace rail.
High-frequency whistling sound
Not a fault. Current state of technology.
► Advise customer:
The switching power supply in the appliance changes its frequency depending on
the power requirement.
When high power is required, the switched-mode power supply works in an
ultrasonic range that cannot be heard by humans.
When low power is required, the frequency drops to a range that is possible to be
heard by humans.
Cooling fan motor makes a high-
frequency noise
(KI01 to KI04 and CPM with software
status 0022 and 0026)
Fan speed not optimised with this software
status.
► Flash CPM to software status ≥ 0027.
(KI01 to KI04 and CPM with software
status 0027)
Not a fault. Current state of technology.
► Advise customer:
This appliance uses newer cooling fan motor technology than earlier ones (BLDC
motor).
The operating noise of the new cooling fan motor differs from the operating noise of
the previous cooling fan motors.
Cooling fan motor whistles at a high
frequency at certain speeds
(KI01 to KI04 and CPM with software
status 0022 and 0026) - (sporadic, on-
ly after several minutes when cooling
down after combined operation of mi-
crowave/hot air)
Noises not optimised with this software
status.
► Flash IaB to software status ≥ 5700.
► Flash CPM to software status ≥ 0027.
(KI01 to KI04 and CPM with soft-
ware status ≥ 0027) - (sporadic, on-
ly after several minutes when cooling
down after combined operation of mi-
crowave/hot air)
Not a fault. Current state of technology.
► Advise customer:
This appliance uses newer cooling fan motor technology than earlier ones (BLDC
motor).
The operating noise of the new cooling fan motor differs from the operating noise of
the previous cooling fan motors.
Cooling fan overrun too loud
(KI01 to KI04 and CPM with software
status 0022 and 0026)
Fan speed is not optimised with this soft-
ware status.
► Flash CPM to software status ≥ 0027.
