iRobot Roomba Discovery, Service Manual, Page: 23 / 87

23
REPL
ACE
M
ENT
PART
Battery
QC
o
Ensure BiT passes.
Failed BiT 7, 8 or 9 – Drive Wheels & Encoders
Roomba Symptom:
o
Roomba spins both forward and backward in
circles and may end in “uh-oh and 4 beeps”.
o
Wheels may not turn or sound loud.
BiT REP
A
IR
STEPS
If the wheel tests fail or sound bad:
Æ Put the Roomba on its back and manually turn the
wheel. Is there an obstruction? Is the axle and bearing
centered?
Æ Open wheel cover and clean under the cove with
compressed air, including wiping the encoder sensors
with alcohol. (A,B,C)
Æ Inspect the drive belt and exchange it if it is very
worn or slipping.
Æ If the motor is dead, attach a new wheel assembly
into pcb and repeat test. If it works, the pcb is good
and the wheel needs to be replaced.