Janome J30 Troubleshooting guide

SERVICE MANUAL
&
PARTS LIST
MODEL: J30
First Edition: 12 February 2019

INDEX
WHAT TO DO WHEN.......................................................................................................................... 1-3
CHANGING EXTERNAL PARTS
FACE COVER .........................................................................................................................................4
FREE-ARM COVER ...............................................................................................................................5
FRONT COVER ......................................................................................................................................6
REAR COVER.........................................................................................................................................7
MECHANICAL ADJUSTMENT
PRESSER BAR HEIGHT ........................................................................................................................8
NEEDLE DROP POSITION.....................................................................................................................9
ADJUSTMENT OF HOOK TIMING .......................................................................................................10
ADJUSTMENT OF NEEDLE BAR HEIGHT..........................................................................................11
CLEARANCE BETWEEN NEEDLE AND TIP OF ROTARY HOOK ......................................................12
FEED DOG HEIGHT .............................................................................................................................13
TOP TENSION ......................................................................................................................................14
STRETCH STITCH FEED BALANCE ...................................................................................................15
REPLACEMENT AND ADJUSTMENT OF THE NEEDLE THREADER PLATE....................................16
ADJUSTING BUTTONHOLE LEVER POSITION..................................................................................17
SELF-DIAGNOSTIC TEST
SELF-DIAGNOSTIC TEST.............................................................................................................. 18-23
TO DISPLAY THE VERSION OF THE PROGRAM...............................................................................23
REPLACING THE ELECTRONIC COMPONENTS
PRINTED CIRCUIT BOARD A CONNECTION .....................................................................................24
PRINTED CIRCUIT BOARD A ..............................................................................................................25
PRINTED CIRCUIT BOARD F2 ............................................................................................................26
PRINTED CIRCUIT BOARD F1 ............................................................................................................27
PRINTED CIRCUIT BOARD L...............................................................................................................28
DRIVING MOTOR (DC MOTOR) ..........................................................................................................29
SWITCHING REGULATOR UNIT..........................................................................................................30
PARTS LIST .................................................................................................................................... 31-45

1
 Condition Cause Howtox Reference
1. Skipping
Stitches
1. Needleisnotinsertedproperly.
2. Needleisbentorworn.
3. Incorrectlythreaded.
4. Needleorthreadare
 inappropriateforthefabric
being sewn.
5. Sewingonstretchfabric.
6. Inappropriateneedlebar
height.
7. Inappropriateneedletohook
timing.
8. Inappropriateneedletohook
 clearance.
Inserttheneedleproperly.
Changetheneedle.
Rethread.
Usetherecommendedsewingneedle
andthread.
UseaHAx#11bluetipneedle.
Seemechanicaladjustment“Adjustment
ofneedlebarheight”.
Seemechanicaladjustment“Adjustment
ofhooktiming”.
Seemechanicaladjustment“Clearance
betweenneedleandtipoftherotary
hook”.
P. 11
P. 10
P. 12
2. Fabricnot 
moving
1. Incorrectfeeddogheight.
2. Feed dog is in down position.
3. Threadonbottomsideof 
 fabricisjammedup.
4.Feeddogteethareworn.
Adjustthepresserbarleveltomake
thepressurestronger.Seemechanical
adjustment“Feeddogheight”.
Raisethefeeddog.
Makesuretobringbothneedleand
bobbinthreadsunderthefootwhenstart
sewing.
Changethefeeddog.
P. 13
WHAT TO DO WHEN

2
Condition Cause How to Fix Reference
3. Breaking 
 upper 
 thread.
1. Initial sewing speed is
 toofast.
2. Threadpathisincorrect.
3. Needleisbentordull.
4. Toptensionistoostrong.
5. Needlesizeisinappropriatefor 
 fabric.
6. Needleeyeisworn.
7. Needleholeinneedle plate is
 wornorburred.
Startwithmediumspeed.
Usetheproperthreadpath.
Replacewithanewneedle.
Adjusttoptensioncorrectly.
Useappropriateneedleforfabricand
threadinuse.
Changetheneedle.
Repairtheholeorreplacetheneedle
plate.
4. Breaking 
bobbin
 thread.
1.Bobbinholderisincorrectly
 threaded.
2.Toomuchthreadiswound 
 onthebobbin.
3.Lintisstuckinsidethebobbin 
 holder.
4.Threadqualityistoolow.
5.Threadisjammingaroundthe 
 bobbinholder.
Setthebobbinthreadcorrectly.
Adjustthepositionofbobbinwinder
stopper.
Cleanthebobbinholder.
Changetoahighqualitysewingthread.
Clearoutthejammingthread.
5. Needle
 breaks
1.Needleishittingtheneedleplate.
2.Needleisbentorworn.
3.Needleishittingthehook.
4.Fabricisbeingpulledtoostrongly
 whilesewing.
Seemechanicaladjustment“Needledrop
position”.
Changetheneedle.
Seemechanicaladjustment“Clearance
betweenneedleandtipoftherotary
hook”.
Guidethefabricgentlywhilesewing.
P. 9
P. 12

3
 Condition Cause Howtox Reference
6.Noisy
operation
1. Backlashbetweenhookgear
 andlowershaftgearistoo
 great.
2. Lowershaftgearisloose.
3.Inappropriatebelttension.
4. Notenoughoil.
5.Uppershaftgearisloose.
Eliminatethebacklash.
Eliminatethelooseness.
Seepartremovalandreplacement
“drivingmotor(DCmotor)”.
Oilallmovingparts.
Eliminatethelooseness.
P. 29
7.Deformation
pattern
1.Inappropriatefeedbalance.
2. Toptensionistoostrong.
Adjustthefeedbalancingscrew.
Seemechanicaladjustment
“Toptension”.
P. 15
P. 14

4
CHANGING EXTERNAL PARTS
FACE COVER
To remove:
1.Removethecapandsetscrewqandliftthefacecovertodisengagetheribontheinside.
 Removethefacecoverw.
To attach:
2.Followtheaboveproceduresinreverse.
q
w

5
FREE-ARM COVER
To remove:
1.Removethesetscrewqand w.
 Movethefree-armcoveretotheleft.
 Removethefree-armcover.
To attach:
Followtheaboveproceduresinreverse.
CHANGING EXTERNAL PARTS
q
w
e

6
CHANGING EXTERNAL PARTS
FRONT COVER
To remove:
1.Removethefacecoverandfree-armcover(Seepage4and5).
2.Removethesetscrewsq(2pcs.).
3.Removethesetscrewsw(4pcs.),backcovere.
4.Removethesetscrewsr(2pcs.).
5.Loosenthesetscrewt.
6.Disengagethefrontcoverandrearcoverhooks.
7.Removethefrontcover.
8.DisconnectalltheconnectorsfromthecircuitboardA.
NOTE:
Donotdisconnecttheconnectorsbypullingoncord.Todisconnect,grasptheconnector,notthecord.
To attach:
7.Followtheaboveproceduresinreverse.See"PRINTEDCIRCUITBOARDACONNECTION".(Page24)
q
ww
e
w
rr
t

7
CHANGING EXTERNAL PARTS
REAR COVER
To remove:
1.Removethefacecoverandfree-armcover(Seepage4and5).
2.Removethesetscrewsq(2pcs.)andthesetscrewsw(3pcs.).
3.Removethesetscrewse(4pcs.)andbackcoverr.
4.Removethesetscrewst(2pcs.).
6.Disengagethefrontcoverandrearcoverhooks.
7.Removethefrontcover.
To attach:
5.Followtheaboveproceduresinreverse.
q
ee
r
e
tt
w

8
6.0 mm
MECHANICAL ADJUSTMENT
PRESSER BAR HEIGHT
Thedistancebetweenthebottomofthepresserfootinuppositionandtheneedleplateshouldbe6.0mm.
1. Removethefaceplateandneedle.
2. Lowerthefeeddogbelowtheneedleplate.
 Placeablock6mmthickunderthe presserfootandlowerthepresserfootlifterw.
3. Loosenthesetscrewq.Raisethepresserfootlifterandtightenthesetscrewqrmly.
 Attachtheneedleandfaceplate.
NOTE:
Makesurethatthepresserfootshouldbeparalleltothefeeddogslotsintheneedleplate.
q
Feed dog slots
Presserfootshouldbeparallel
tothefeeddogslots.
w

9
0.2 mm
ormore
0.2 mm
ormore
A = B
MECHANICAL ADJUSTMENT
NEEDLE DROP POSITION
Setthestitchpatternto“”.Thestandardneedledroppositionshouldbeatcenteroftheneedleplatehole.
Selectzigzagstitch“”,andsetthestitchwidthat“7.0”.Theclearancebetweentheneedleandtheedgeof
theneedleholeshouldbeatleast0.2mmoneitherside.Ifnot,adjustasfollows:
1. Turnthepowerswitchoff.Removethefacecover.(Seepage4.)
2. Loosenthehexagonalsocketscrew3x4q.Adjusttheneedledroppositionbyturningtheeccentricpin.
 ThedirectionofeccentricpinshouldbeasshowninFig.1.
3. Attachthefacecover.
NOTE:
Checkthehooktimingafterthisadjustment.
needleplatehole
w
Fig. 1

10
Theamountofascendingtraveloftheneedlebarfromitslowestpositiontotheposition()wherethetipof
therotaryhookexactlymeetstherightsideoftheneedleshouldbe3.25to3.55mm.
1.Removetheneedleplateandbobbinholder.
2.Turnthepowerswitchon.
3.Selectthepattern(leftposition).Setthezigzagwidthat0.
4.Removethefree-armcover.(Seepage5.)
 Turnthehandwheeltowardyoutolowertheneedleatitslowestposition.
5.Loosenthehexagonalsocketscreww(2pcs.).
6.Movetheneedlebar3.4mmfromthelowestposition.
7. Turnthelowershaftgearuntilthetipofhookmeetstherightsideoftheneedlewhileholdingthehandwheel.
8.Tightenthehexagonalsocketscreww(2pcs.).
9.Attachthefree-armcover,bobbinholderandneedleplate.
MECHANICAL ADJUSTMENT
ADJUSTMENT OF HOOK TIMING
w
Needle plate
Bobbinholder
w
Lowershaftgear
Leftposition()
(#14)
Tipofhookmeetsthe
rightsideoftheneedle
Lowest needle position
3.25 – 3.55 mm

11
Beforeproceedingwiththisadjustment,checkthehooktiming(refertopage10).Thedistancebetweenthe
upperedgeoftheneedleeyeandthetipofthehookshouldbeintherangeof1.6to2.0mmwhenthetipofthe
hooktimingmeetsrightsideoftheneedleintheleftneedleposition()astheneedleascendsfromitslowest
position.
1.Removetheneedleplate,bobbinholderandfaceplate.
2.Turnthepowerswitchon.
3.Selectthepattern(leftposition).Setthezigzagwidthat0.
4.Turnthehandwheeltowardyouuntilthetipofhookmeetstherightsideofthe needle.
5.Loosenthehexagonalsocketscrewq.
6.Movetheneedlebartoadjusttheneedlebarheight,andtightenthehexagonalsocketscrewq.
 Becarefulnottoturntheneedlebar.
7. Attachthebobbinholder,needleplateandfacecover.
MECHANICAL ADJUSTMENT
ADJUSTMENT OF NEEDLE BAR HEIGHT
1.6 – 2.0 mm
q
Needle setting
groove
Upperedgeofneedlehole
Hookrace(unit)
Hookrace
Tipofhookmeetstherightsideoftheneedle
Leftposition()
(#14)
Needle plate
Bobbinholder

12
Adjustment procedure:
1.Removetheneedleplateandbobbinholder.Attachthemasterneedle.Turnthepowerswitchonandsetthe
 zigzagwidthatmaximum.
2.Removethefacecover.(Seepage4.)
3.Loosenthesetscrewsq(2pcs.).
4.Turnthehandwheeltowardyou.Adjusttheclearancebetweentheneedleandthetipoftherotaryhook,by
 movingthehookbaseplateupordown,towithin–0.1to+0.05mmattheleftandrightneedleposition.
5.Tightenthesetscrewsq(2pcs.).
6.Attachthefacecover.Removethemasterneedle.Attachthebobbinholderandneedlepate.
7. Checktheclearancebetweentheneedleandtheedgeoftheneedleholeintheneedleplate(seepage9).
*Theclearancebetweentheneedleandthepointofhookshouldbe–0.1to+0.05mm.
CLEARANCE BETWEEN NEEDLE AND TIP OF THE ROTARY HOOK
MECHANICAL ADJUSTMENT
–0.1to+0.05mm
Needlebarsupporter
adjustingplate q
Needle plate
Bobbinholder
Tipofhook

13
Thehighestpositionofthefeeddogshouldbebetween0.80and0.90mmfromthesurfaceoftheneedle
plate.
1.Lowerthepresserfootandturnthepowerswitchon.
2.Turnthehandwheeltowardyoutosetthefeeddogatthehighestposition.
3.Removethefree-armcover.(Seepage5.)
4.Loosenthesetscrewqand nut w.
5.Adjustthefeeddogheightbyturningtheadjustingscrewe.
 Thehighestpositionofthefeeddogshouldbebetween0.80and0.90fromthesurfaceoftheneedleplate.
6.Tightenthenutwandsetscrewq.
7. Attachthefree-armcover.
FEED DOG HEIGHT
MECHANICAL ADJUSTMENT
A B
e
w
Presserfoot
Feed dog
0.80 – 0.90 mm
Surfaceoftheneedleplate
q

14
MECHANICAL ADJUSTMENT
TOP TENSION
Thetoptensionshouldbebetween65and80gwhenpullingthethreadupinthedirectionofarrow.
*Usepolyestersewingthread#50(White).
*Ifitisnotwithintheabovelimit,adjustasfollows.
1.Setthetensiondial“4”.
2.Removethefacecoverandfrontcover.(Seepage4and6.)
3.Lowerthepresserfoot.
•Ifthetoptensionistooloose,turntheleadscrewinthedirection(A).
•Ifthetoptensionistootight,turntheleadscrewinthedirection(B).
4.Checkthetoptensionandattachthecover.
Whitepolyesterthreadsize50
Pullthethreadatthespeedof110mm/secinthedirectionofarrow
Cover

15
MECHANICAL ADJUSTMENT
STRETCH STITCH FEED BALANCE
To check:
1. Entertheself-diagnosticmode(seebelow).
  AttachtheSatinstitchfootF.Placeafabricunderthepresserfoot.Lowerthepresserfoot.
2. Pressthelockingstitchbuttontostarttestsew,andchecktheresults(thestandardgurelengthof5 
  piecesofgure8is33-39mm).
3. Ifstretchpatternsaredistorted,correctthemwiththefeedbalancingdial.
  Ifstretchpatternsaretoodeformedandcannotbecorrectedwiththefeedbalancingdial,adjustasfollows.
To adjust:
1. Removethefeedbalancingdialcover.Turnthedialatstandardpositionasillustrated.
  TurnthepowerswitchON.
  Selectthestraightstitchandsetthestitchlengthat“0”.Placeafabricunderthepresserfoot.
  Lowerthepresserfoot.(Donotsetbobbinandneedlethreads)
2. Turnthehexagonalsocketscrewtothelefttoloosenit.
  Movethegearup(A)ordown(B)toadjustthefeed.
  *Donotmovethegearrightorleftwhenadjusting.
  Startthemachineandcheckthemovementofthefabric.
  Adjustthehexagonalsocketscrewposition(gearposition)untilthefabricwillnotbefedwiththestitch
  lengthsettingat“0”.
3. Tightenthesocketscrewandattachthefeedbalancingdialcover.
  Entertheself-diagnosticmodeandtestsewagain.Checkthatthestandardlengthof5piecesofgure8is
  33-39mm.Ifnot,turnthefeedbalancingdialtocorrectit.
36–39mm
Correct IncorrectIncorrect
Feedbalancingdial
(Standardposition)
Hexagonalsocketscrew
Feedbalancingdialcover
(A)
(B)
TO ENTER SELF-DIAGNOSTIC MODE:
Turnthepowerswitchonwhile
simultaneouslypressingauto-
lockbuttonandneedleup/down
button.
TheLCDdisplaywill
indicate“01”.
Pressthevaluesetkey
7timestodisplaythe“08”.
Pressthe start/stop
buttontodisplaythe
“88”and toenter
thestretchstitchtest
mode.
Gear
Thestandardgurelengthof5piecesofgure
8is33-39mm

16
X
Threaderplate
supporter
Threader
positioning
plate
FIG. 3
Pin
Adjustmentofleftorrightdirection
Threaderplate
Nut w
Viewfrom"X"
q
Verticaladjustment FIG. 2
REPLACEMENT AND ADJUSTMENT OF THE NEEDLE THREADER PLATE
Ifthehookofthethreaderplateisdamaged,changeandadjustthepartasfollows:
TO CHANGE THE THREADER PLATE:
1. Pushdowntheneedlethreaderknobandpullthethreaderplatesupporterdowntoremoveit(seeFIG1).
2. Toinstalltheneedlethreaderplate,linethegrooveupwiththepinandpushituptosnapt.
TO ADJUST THE THREADER PLATE POSITION:
1. If the hook on the threader positioning plate touches the top or bottom side of the needle hole, loosen
setscrewqandadjustthehookposition(FIG.2).
2. Ifthehookonthethreaderplatetouchestheleftorright side of the needle hole, loosen setscrew wand
adjustthehookposition(FIG3).
Replacingthethreaderplatesupporter
(withthethreaderplateattached) FIG. 1
MECHANICAL ADJUSTMENT

17
BHsensor
1.6 mm gap
TO ENTER ADJUSTING MODE
MECHANICAL ADJUSTMENT
ADJUSTING BUTTONHOLE LEVER POSITION
TO ADJUST THE BUTTONHOLE LEVER GUIDE:
1. Enterthediagnostictestofbuttonholesensormode.(Seepages18and19.TheLCDshoulddisplay03and
 BHsymbol.)
2. Removethefacecover(seepage4)andloosenthesetscrewq.
3. MovethebuttonholeleverguidesotheBHsymboldisappearwhenthebuttonholeleverislowered.
 Tightenthesetscrew.
TO ADJUST THE BUTTONHOLE SENSOR POSITION:
4.Attachthebuttonholefoot(R).
5.Lowerthebuttonholelevertoitslowestpositionandopena1.6mmgapbetweenthesliderandthe
 buttonholefoot.
6. TurntheadjustingscrewwtotheleftuntiltheLCDdisplayBHsymbol.
7. Next,turntheadjustingscrewtotherightuntiltheBHsymboldisappears.
8. Turnoffthepowerswitch.
9. Attachthefacecover.
q
Buttonholeleverguide
Buttonholefoot(R)
Buttonholelever
w
NOTE:
Ifthereisanylintordustinthebuttonholesensorslit,loosenthescreweandcleanitoutwithaswab.
e

18
TO ENTER SELF-DIAGNOSTIC MODE:
Preparation:
 1.Turnthepowerswitchoff.
 2.Movethebobbinwinderspindletotheleft.
 3.Raisethefeeddog.
 4.Setthespeedcontrollevertotheleft.
 5.Removethepresserfootandraisethepresserfootlifter.
 6.Turnthehandwheeltowardyoutoraisetheneedletoitshighestposition.
NOTE:
 •Becareful:thesewingmachinemaystartrunninginitsownwhileintestmode.
 •Turnoffthepowerswitchbeforereplacinganyparts.
 •Repeatthediagnostictestuntiltheproblemhasbeenresolved.
 •Youcanskipstepsinthediagnosticprocedureandgodirectlytothetestyouwanttoperform.
 (Enterself-diagnosticmode,thenselectthestepnumberofthediagnostictestyourequirebypressing
the  
start/stopbutton .)
To begin:
 Turnontheswitch.Ifanyofthefollowingproblemsoccur,taketherecommendedactionsintheorderthey
 areshown.
1.Themachinedoesnotrespondwhenthepowerswitchisturnedon:
 •Checkeachconnectorconnection
 •Replacethemachinesocket
 •Replacetheswitchingregulator
 •ReplacetheprintedcircuitboardA
2.Thesewingmachinelampdoesnotlightup:
 •Replacethelightbulb
 •ReplacetheprintedcircuitboardA
SELF-DIAGNOSTIC TEST
1. Turnthepowerswitchonwhile
  simultaneouslypressingauto-lock
  buttonandneedleup/downbutton.
2. TheLCDdisplay
  willindicate“01”.
3. Pressthe start/stop
button to enterthe
  self-diagnosticmode.