Milwaukee M12 2401-20- User Manual

MILWAUKEE ELECTRIC TOOL CORPORATION

13135 WEST LISBON ROAD • BROOKFIELD, WISCONSIN 53005 USA

(262) 781-3600

TO:

AUTHORIZED

portable electric tool

SERVICE STATIONS

DATE

:

March 2009

factory

SERVICE CENTERS

TOOL(S) \ PRODUCT(S)

AFFECTED:

2401-20 M12 Screwdriver, 48-11-2401 12V Compact Lithium-Ion
Battery Pack, 23-66-1095 Electronic Switch Module Assembly

SUBJECT:

“23-66-1095 Electronic Switch Module Assy versus 48-11-2401 12V Compact
Lithium-Ion Battery Pack”

Symptom

Possible Cause(s)

Solution(s)

switch -
trigger

‘quick-pull’

–

no power

Battery Pack

An aged / used 48-11-2401 12V battery Pack can lead to the
impression of a bad 23-66-1095 Switch in the M12 Screwdriver – if
the

trigger can be pulled slowly and deliberately versus a

‘quick-pull’

allowing the tool to turn-on and run

– the battery pack

is to blame.

switch

no power

Switch electronics FET

Switch electronics FET may be faulty – attempt to run screwdriver
with known-good battery pack.

Battery Pack connected
to Charger -

alternately

flashing red/green
Charger lights

Bad connection between
Battery Pack and Charger

battery pack only part-
way-in-charging-bay

and/or ‘rocked’/ moved
during charge cycle

Aged / Used Battery Pack -

Faulty Battery Pack -

FULLY seat battery pack into charger

– a slight tap on the battery

pack may be needed to fully seat pack.

NOTE:

with

alternately

flashing red/green Charger lights

unplug

the Charger from power

source and let it sit until the lights stop flashing – this allows circuit
board capacitor to self discharge.

A

fully charged

aged / used battery pack can cause a flashing

red/green condition;

run/drain battery pack and retry charging on

known good Charger. If Battery Pack takes a normal charge it is
functional -

if the period of run time becomes noticeably shorter with

a normal charge, this indicates the end of the Lithium Ion battery
packs service life; customer should replace battery pack with a new
Lithium Ion battery pack.

Pack may not be accepting charge or switch electronics FET may be
faulty. Attempt to charge Battery Pack on known-good Charger.

Tool’s Battery Pack fuel
gauge drops to

NO

lights after one or two
screw insertions – no
LEDs lit or blinking.

DEFECTIVE Battery Pack

Battery Pack shows four lights, and then –

battery pack is ‘dead’

–

fuel gauge drops to

NO

lights after one or two screw insertions and

fails to rebound after 30 seconds of non-use

Battery Pack Protection

Battery Pack Protection -

to protect itself from damage and extend

its life, the battery pack’s intelligent circuit monitors current draw and
temperature. In extremely high torque, binding, stalling, and short
circuit situations,

the battery pack will turn OFF the tool if the

current draw becomes too high

. In these situations, the tool will

"buzz" for about 5 seconds before it turns OFF. To reset, pull and
release the trigger. Under extreme circumstances, the internal
temperature of the battery could become too high;

the battery pack

will then shut off

.

This bulletin is for informational purposes. PLEASE NOTE ON SERVICE PARTS LIST: 54-04-2400, 54-42-2400

TO INFORM YOU

PRODUCT
SUPPORT

BULLETIN

#

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