BLACK+DECKER LCS1020 Repair Manual

Comprehensive repair guide for the BLACK+DECKER LCS1020 cordless chainsaw, including troubleshooting, maintenance, and repair instructions for 24 common faults.

$39.99

Last updated Aug 1, 2026, 1:13 AM

About this manual

Comprehensive repair guide for the BLACK+DECKER LCS1020 cordless chainsaw, including troubleshooting, maintenance, and repair instructions for 24 common faults.

0% Reported Successful Repair

Price

$39.99

Full Manual Includes

root cause analysis
tools needed
step-by-step repair procedure
diagrams
exploded views
post-repair checks

Table of contents preview

Black+decker Lcs1020
The Six Things That Matter Most
What This Model Actually Has
Indicator And Signal Map
Model-revision Warning
The Cutting Path
Normal Use Sequence
Normal Behavior That Can Look Like A Fault
What This Model Does Not Have
The Saw
Unusable
FM-08 CHAIN IS LOOSE, SAGS, OR WILL NOT HOLD TENSION
FM-20 ABNORMAL GRINDING, RATTLING, OR SEVERE VIBRATION
FM-09 CHAIN IS TOO TIGHT, BINDS BY HAND, OR BAR AND CHAIN OVERHEAT
FM-21 GUIDE BAR, SAW CHAIN, SCABBARD, OR CUTTING ATTACHMENT IS

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Likely Root Causes

Debris, resin, or chips in the battery rails
Damaged or swollen battery housing
Jammed release button or latch
Bent tool battery well or contact support
Wrong or incompatible battery pack
Resin, dirt, or debris around the controls
Cracked or distorted rear-handle housing
Broken return spring or linkage
Worn or welded trigger-switch contacts
Loose internal wiring
New chain has stretched during break-in
Bar-adjust locking knob was not tightened
Chain tension was set incorrectly
Worn chain, bar groove, or tensioner parts
Chain was adjusted while hot
Chain was over-tensioned
Chain or bar is dry
Guide-bar groove or oil hole is clogged
Wrong or damaged chain is installed
Bar rails or drive links are burred
Knob was overtightened or cross-threaded
Resin, chips, or dirt in the threads
Tensioner tab is outside its slot
Stripped knob, bolt, cover, or tensioner teeth
Cracked sprocket cover
Chain is off the drive sprocket
Drive links are jammed in the bar groove
Broken chain or damaged drive links
Stripped or broken drive sprocket
Internal gearbox failure
Chain was fitted with cutters facing backward
Chain was reversed during cleaning or replacement
Direction marks were overlooked
Cover was assembled before orientation was checked
Dull, chipped, or damaged cutters
Incorrect chain tension
Dry bar and chain
Chain contacted soil, stone, wire, or a nail
Worn guide bar or wrong chain
Cutters on one side are duller or shorter
Unequal depth gauges
Burred or uneven guide-bar rails
Bent guide bar
Uneven or incorrect chain tension
Chain was too loose
Worn or damaged drive links
Bent, pinched, or badly worn guide-bar groove
Damaged drive sprocket
Cover, tensioner, or locking knob did not hold
Oil level is too low
Primer was not pressed fully or long enough
Guide-bar oil hole or groove is clogged
Wrong, waste, or overly thick oil
Blocked or failed primer or internal feed path
Wood closes on and pinches the bar
Motor or gearbox has excessive internal load
Log or limb support let the kerf close
Tensioned branch moved during the cut
Saw was twisted in the kerf
Cut sequence did not match how the log was supported
Bar or chain was already crooked or loose
Oil cap is loose, cross-threaded, or dirty
Reservoir was overfilled
Saw was stored on its side or in heat
Cap seal, primer, reservoir, or oil tube is cracked
Housing seam is damaged
Impact or age cracked the plastic
Cap threads or seal are damaged
Primer bulb hardened, split, or detached
Indicator window is cracked or clouded
Reservoir neck or housing is distorted
Loose bar, cover, or handle hardware
Chain is dry, loose, damaged, or off the sprocket
Debris is trapped under the cover
Worn drive sprocket or gearbox
Motor bearing or internal housing fault
Chain hit soil, stone, metal, or a hard foreign object
Bar was bent in a pinch or impact
Chain derailed or broke
Wrong chain or bar was installed
Scabbard was crushed, cut, or lost
Damaged or aged battery cells
Shorted or contaminated terminals
Wrong or failed charger
Charging outside the allowed temperature range
Impact, water, fire, or internal electrical failure
Water or oil entered electrical areas
Internal short, stalled motor, or wiring failure
Damaged battery contact block
Melted switch or motor insulation
Cracked housing exposed live components
Drop, impact, or crush damage
Loose or missing fastener
Age or chemical damage to plastic
Overtightened or stripped mount
Using the guard or scabbard as a carrying handle
Chain is not fully in the guide-bar groove
Cutters face the wrong direction
Chain is not around the drive sprocket
Bar slot is not on the mounting bolt misaligned
Tensioner was not returned to its stop or tab is

Supported model

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BLACK+DECKER

Bdcr20c

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BLACK+DECKER

Bdcdd12c

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BLACK+DECKER

Ld120va

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BLACK+DECKER

Bdci20c

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The battery will not slide fully into the tool, click into place, stay latched, or release normally.

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The chain travels around the bar but only rubs the wood, produces almost no chips, and will not enter the cut.

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The saw chain leaves the guide-bar groove, hangs from the bar, or comes off the drive sprocket.

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Bar oil forms a fresh puddle, runs from the cap, or appears from the body while the saw is idle or stored.

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The cap will not close, the primer is split or stuck, or the oil-level indicator is cracked, clouded, or leaking.

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The saw cuts slowly, makes fine dust instead of chips, chatters in the kerf, or must be pushed hard despite judging sharpness.

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The lock-off or trigger will not move freely, does not return, responds intermittently, or the motor continues after the trigger is released.

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The reservoir contains oil but the chain stays dry, the primer gives no visible result, or the bar oil path remains dry.

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Saw dead with charged pack

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The saw makes new grinding, clacking, rattling, or strong vibration during no-load running or cutting.

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After chain or bar work, the cover will not sit flush, the bar will not align, or the locking knob cannot begin correctly.

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The bar is bent or cracked, chain links or cutters are broken, or the guide-bar scabbard is split, missing, or will not stay on.

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Motor runs, chain does not

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The guide bar steers sideways in the cut or the kerf curves even though the workpiece is supported and the saw is held square.

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Chain moves but does not cut

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The guide bar cannot be withdrawn from the kerf, the chain is trapped, or the workpiece closes on the saw.

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The lithium battery or charger shows abnormal heat, swelling, cracking, electrolyte, hissing, odor, sparks, or smoke.

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The chain hangs below the guide bar, can be pulled too far from the rail, or becomes loose again after adjustment.

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Liquid entered the tool, the housing emits smoke or sparks, plastic melts, a burning odor appears, or wiring or contacts are exposed.

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The chain is hard to pull around the bar, the bar becomes unusually hot, or smoke appears without an electrical odor.

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The front hand guard, front or rear handle, main housing, ribbed bumper, fastener, battery well, or another external part is cracked, loose, or missing.

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A tool-free knob is frozen, cross-threaded, spins without effect, will not clamp the bar, or cannot hold the set tension.

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The motor can be heard, but the chain remains stationary or only twitches while the trigger is held.

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FM-01: FM-01 BATTERY PACK WILL NOT INSERT, LATCH, OR RELEASE

Summary

Battery pack will not insert, latch, or release properly, preventing tool operation.

Full repair guide includes

Root Cause Analysis
Required Tools
Replacement Parts
Step-by-step Repair Procedure
Safety Precautions
Verification Checklist

BLACK+DECKER LCS1020 Repair Manual

Manual information

About this manual

Full Manual Includes

Table of contents preview

Likely Root Causes

Supported model

Related Models

Common Symptoms

Failure Modes

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