Husqvarna 6690 User manual

1
SERVICE-ROUTINE
6690
Husqvarna

2
Directions for use
Theseserviceinstructionsareintendedtobeused
byserviceworkshoppersonnelorbysalesmenwho
carryout servicing intheirowndistricts themselves.
Theyassume athoroughknowledgeof thehandling
of precision appliances and accessibility to service
tools.
Themanualisdividedintothreesectionsand
includesall servicepoints and checks which should
becarriedoutduringa complete overhaul of a
sewingmachine.The first sectionincludesthe
controlof the a equate functioning of integral details.
Thesecond section deals with the various settings
which mustbe maintainedto ensurethat the
machinefunctions in a satisfactory way.
Thethird sectiondealswithdismounting, mounting
andsettingtheelectronic units included inthe
machine.
Thediagramsonlygiveanindicationastowhere
thedetail or mechanism mentioned is located in the
machine.Formoredetailedinformationregarding
theconstruction, etc., refer to thediagramsinthe
sparepartslist. The codings of the details referto
thesediagrams-as an example, detail 5/37 can be
seen in the spare parts list on page 5, pos. 37.
Contents Page
Visualcontrolofdetails 3-9
Settinginstructions 10-29
Electronicunits 30-44
Thefollowing details shouldbevisuallychecked
See page
Stitchplate 3
Presserfoot 3
Feed dog 3
Bobbin case 4
Hookcover 4
Hook 5
Driver 5
Cog belt 6
V-belt 6
Reductiongear 7
Terminalboard 7
Motor 8
Footcontrol 9

3
The stitch plate
Thestitch plate must not be damagedinanyway.
Particularattentionshouldbe paid to possible
damageor unevennessaroundtheneedle hole.
Action
Exchangethe damaged stitch plate.
Spare parts: See RA, page 4.
OrderingNo:Stitchplate: 4115628-01.
Presser foot
Requirements
Thereshould be no scratches ontheundersideofthe
presserfoot.
Action
Exchangethe presser foot if there are scratches on the
underside.
Comments
Howthefabricisheldbetweenthepresserfoot and the
stitchplate plays an important roleinthestitchformation.
Spare parts: See RA, page 22.
Ordering No: Zig-zag presser foot 411 1383-01
Utilitystitchandpatternpresserfoot411 4512-01.
The feed dog
Requirements
Theupper side of the feeddog (10/1) must notbe
damagedin any way, e.g. broken teeth, etc.,and
should befreefromfluffandpiecesofthread.
Action
Thefaulty feeddogshouldbe exchanged.Removethe
stitchplate. Undo the screws (10/2) and remove the feed
dog. As regards the setting of the feed dog in relation to
thestitch plate groove, see page 23.
Spare parts: See RA, page 10.
Ordering No: Feed dog 411 5910-01.
Upper side Underside
Zig-zag presser foot 411 1383-01
Utilitystitch andpattern
presser foot 411 4512-01.

4
The bobbin case
Fabricdressing may fasten under the thread tension
springand cause the thread tension to change.This
canbe removed by means of a needle, which should
beinsertedbetweenthe spring and the bobbin case.
Spare parts: See RA, page 9.
Ordering No: Bobbin case 401 1530-02.
Depositsfromthefabricorthreadcan fasten on the
spindleofthehookandcause noise. If such is the
case,the spindle shouldbecarefullycleanedwith
thebrushin the accessory box. At the same time
makesurethatpiecesofthreadwhichhavebecome
woundround the spindle are removed.Inbadcases,
exchangethe bobbin case.
Spare parts: See RA, page 9.
Ordering No: Bobbin case 401 1530-02.
The hook cover
Requirements
Theinsideofthe hook cover must not be
damaged.Bothaxial and radial movement
shouldbepossible.
Action
Exchangethe hook cover if it isdamaged.
Checkthat the holes in the hook cover are not
blockedand that the shoulder screwsandthe
holdersarenot damaged. Regarding the gap
betweenthehookcoverandthedriver,see page 21.
Comments
Theinsideofthe hook cover makes a support for
thehookandthe bridge above the finger of the bobbin
casesupportsthethread,sothatthethreadloopis
formedontherightsideoftheneedle.Thepossibility
ofmovementinthe hook cover is a prereguisite to
avoidunnecessary noise.
Spare parts: See RA, page 9.
Ordering No: Hook cover 411 6662-01.

5
The hook
Requirements
Thehookmustnotbedamaged.Specialattention
shouldbegiventoseethatthetiphasnot been
damagedor worn, causingburrsorunevenness.
Action
Exchangedthe damaged hook.
Spare parts. See RA, page 9.
Ordering No: Hook 401 1521-01.
The driver
Requirements
Thesurface of the driveragainstthehook must not
bedamaged, wornorunevenin any waywhich
mighthinder the passage of the thread.
Action
Thedamaged driver (9/10) should be exchanged.
Turn thehandwheeluntil theneedleisatthe highest
position.Theslotinthedriverisnowinthe middle,
underneaththe feed dog.Undothethree screws
(9/16)which holdthehookcover-remove the
hookcover andthehook. Then undothethree
screws(9/11)inthedriver, and exchange it for
anewone.Notethepositionoftheslotin the
driver.Thereafter “Thedistancebetweenthe hook
andtheneedle”shouldbecheckedaccordingto
page21,“Thegapbetweenthe hook cover and
driver”according to page 19, and“Setting the
timingforthe hook in relation to the needle”
according to page 20.
Spare parts: See RA, page 9.
Ordering No: Driver 411 6415-01.

6
The cog belt
Thebelttensionshouldnotbesoloosethatitpermits
slippingwhenthemachineislockedandthefoot
controlisdepressed.Tightertensionmakesmore
noise.Thebelt should not be damaged.
Adjustment
Thescrews (14/8, 9) in the reduction gear holder
areaccessibleby means of two holes inthelarge
cogwheel (14/29). If both the screws are loosened,
acertainadjustmentispossiblebymowingthe
framefor the cog wheel journal (14/20, 25, 26)
oneway ortheother.
Tightenthescrews.
Spare parts: See RA, page 14.
The V-Belt
Requirements
Thebelt tension should not be too tight or too
loose.Theslightestamountofslippingis
permissiblewhen the handwheelisheld
firmlyand the foot controldepressed.
Adjustment
Thescrews(14/8,9) in the reduction gear
holderareaccessible by means of two
holesin the large cog wheel (14/29) If
boththescrewsareloosened,acertain
adjustmentis possible by mowing the
reductiongear.
Spare parts: See RA, page 14.

7
The reduction gear
Somechange inthesoundlevel when usingthe
reductiongearisnormal. The gear should be
exchangedonly if thesounddeviation is very
noticeable.
Dismantling
Setthe thread take-up lever at the lowest position,
removethe handwheelandthen takeawaythebelt
guard,printed circuit and cog belt. Unscrew the
screw(14/12)inthebase plate and loosen the
screws(14/36) in the holder (14/6). The
screws(14/8,9)in the reduction gear are
accessiblethrough the holes in the large
cogbelt wheel.Removebothscrews, turn
theholder and liftoutthereductiongear.
Mountingofthereduction gear is done by placing
theframe(14/20)insidetheholderandscrewingin
thescrews (14/8, 9). Replace and tighten the screws
(14/36,14/12).Checkthatthestar lock washer is in
place(14/35)andcheck the tension. Replace the
beltguard andhandwheel,makingsure that the
threadtake-upleverisatthelowestpositionand
themetal latchonthe handwheelpointsupwards.
Spare parts: See RA, page 14.
The terminal board
Checkall connections and cables.
Ifthereisinterferenceinradio or television
receptionfrom themachine,exchangethe condenser.

8
The motor
Control of function
Thefunctioning of themotorcanbe checked without
dismountingtheprintedcircuit.Useaspare part circuit
andconnect it to the connections on theterminalboard
andtest the machineintheordinary way.
Themotornoiseisaffected by the load and the belt
tension.Only motorswhichhave anoiselevel
considerablydeviating from normal shouldbe
exchanged.
Dismantling
Setthe thread take-up lever at the lowest position,
removethe handwheelandthen takeawaythebelt
guard,rearcoverandthecogbelt.
Pullout theplugbythe motor andremovethe
screws(5/16)in the base plate; fold under the
connectionterminal board.Thenremove the
screws(14/36)inthe holder of the reduction gear
andlift out the motor. Mounting is done inthe
reverseorder.Checkthebelttension.Replace
andfasten the rear cover,beltguardand
handwheel,makingsurethat thethread
take-upleverisat the lowest position and that
themetal latchonthe handwheelpointsupwards.
Spare parts: See RA, page 16.

9
The foot control
Requirements
Thespeed shouldbecontinouslycontrollable from
100 r/min to full speed.
Theconnectors to boththewallsocketand the
terminalboradmustnot be damaged or deformed.
Action
Testthe foot controlonamachinewhich is known
tooperate normally.
Ifa satisfactory result is notobtainedexchange
the faultyfootcontrol.
Ifthe cable or plug are damaged, exchange the
damaged part.
Spare parts: See RA, page 17.
+20
-0

10
Setting instructions
The best results will be obtained if you make the
Settings in the following order at each service.
Contents See
page
Setting ratings 11
Gauges 11
Service tools 12
Arm shaft.
Axialplay 14
Lower shaft.
Axialplay 14
Arm shaft circuit.
The zig-zag movement of the needle 15
Needle bar frame.
The setting of the needle at right
angles to the feeding direction 16
The setting of the needle in the
feedingdirection 17
The stop, needle bar frame 18
Thehook.
The distance between the hook
and the needle 19
The timing of the hook in relation
to the needle 20
The gap between the hook cover
and the hook 21
The needle bar.
The upper position of the needle 22
The feed dog.
The stitch plate 23
The position of the feed dog in
relation to the stitch plate groove 23
The lateral setting of the feed dog 24
The height of the feed dog 24
The setting of the feed dog in
relation to the needle 25
Lowering of the feed dog 25
The presser bar.
Tangentialsetting 26
Presser foot pressure 26
Upper thread tension.
Thread tension release lever 27
Setting the thread tension knob 27
The thread take-up spring.
The spring force 28
The adjustment casing 28
The lower thread tension.
The thread tension of the bobbin case 28
The stitch length
The balance between forward
and reverse feeding
Buttonhole 29

11
Setting ratings
Areasonable requirement in a domestic sewing machineis that it should be able tosew
alltypesof fabrics used in the home. The settings made when assembling and sewing-in
themachinesarethosemostsuitedtogivethebestresultsin the majority of fabrics and
fabriccombinations.Indoing so, consideration has been given to the requirements of
differentmarkets.Thisdoes, however, meanthatwhensewingextreme fabrics, better
resultsmaybeobtained in certain cases by altering the settings. It must be pointed out
thatthese altered settings can cause poorer results on more normalfabrics.Howthe
differentstandardratingsaresetcanbeseenfromthedescriptionunder each setting
instruction.Thefollowing list of setting guides and service tools is chiefly intended as an
indicationastohow service men or service workshops should beequipped.
Gauges
1. Service needle. Ordering No. 411 5818-01,
setof 3. Whenmakingseveraladjustments, the
needleisusedasasettingguide.However,even
needlesof the bestqualityaremanufactured with
toleranceswhich canaffectthesetting result.
Theseareneedleswhichareselectedfrom
ordinaryproduction, so thatnominalvaluesare
obtainedwith great accuracy. The service needle
issize90and when setting in the feeding direction,
theneedleshouldbesetinthemiddleoftheneedle
hole. Compare page 17. The service needles are
delivered in sets of 3, packed in glass tubes.
2. Setting needle. Ordering No. 411 5800-01. For
checkingthe maximum gap between theneedle
and hook, according to page 19.
3.Gaugeforthe hook. Ordering No. 411 1752-01.
Settingtheloopformingdistance.Tobe used
accordingtoinstructionsonpage 20.
4.Gaugeforgapbetweenthehookcover and
driver. Ordering No. 411 1649-01. Tobe used
accordingtoinstructionsonpage21.Gives the
same rating as setting guide 411 1635-01, which
hasbeen discontinued.
5.Gaugeforpresserbar. Ordering
No. 411 5151-01. To be used according to
instructionsonpage 26.
6.Gauge for feed lift.Ordering No. 411 1735-01.
To be usedaccording to instructions on page24.

12
Service tools
Boxspanner
To be usedaccording to instructions on page16.
Ordering No. 411 1907-01.
Adamkey
To be used according to instructions on pages 16 and 17.
Ordering No. 411 5844-01.
3.Settingkeyforfeedingbalance.
To be usedaccording to instructions on page43.
Ordering No. 411 6679-01.
4.Hexagon key for the drive wheel of thestepmotor.
To be used according to instructions on pages 35
and4.
5.Adjustment key for setting the lowest speed of the
machine.
To be usedaccording to instructions on page33.
Motorcover
Thewiringintheterminalboardwillbeexposed
whenremoving therearcover.Themotorcover
mustalways be used for safety reasons if the
machineis connected to the electricity, after the
removalof the rearcover.
Ordering No. 411 5862-01.

13
Tool set. Ordering No. 411 1921-01 containing the following details:
1. Flat-nosepliers with wirecutter. Ordering No. 414 4906-01.
2. Brushwith steel wireshaft Ordering No. 401 5016-01.
3. Screwdriverwith glow lamp Ordering No. 411 1904-01.
4. Screwdriver. Wide Cl Fall Ordering No. 411 1901-01.
5. Hammer.Tors No. 1 Ordering No. 411 1905-01.
6. Screwdriverwith screw holder Ordering No. 411 1903-01.
7. Screwdriver. Long Cl Fall Ordering No. 411 1902-01.
8. Pliersforclampingring Ordering No. 411 1910-01.
9. Box spanner, See page 16 Ordering No. 411 1907-01.
10. Tool-case Ordering No. 411 1915-01.
InadditionaPhilip screwdriver may also be ordered.
Philipscrewdriver with two
separate headsOrdering No. 411 5433-01.
Philip screwdriverwith fixedhead Ordering No. 411 1922-01.

14
The arm shaft, axial play
Theaxial bearing shouldenablethe shaft torun
freelyduringthewhole turnand thereshouldnot
beany axial play.
Adjustment
Setthe thread take-up lever atthelowest
position,remove the handwheelandthen take
awaythe belt guard. Loosen the stop screws
7/5on the belt wheel. Pressthearmshaftwith
onehand in the direction of the arrow and push
thebelt wheel in the opposite direction. Then
tightenthe stop screws,commencingwiththe
onewhich is touching the milledplateonthe
armshaft. Checkthatthe armshaftruns freely
duringthe wholeturnandthat there isnoaxial
play.Replace the beltguardand handwheel,
makingsure that the thread take-up lever is at
thelowest position and the metallatchonthe
handwheelpointsupwards.
The lower shaft, axial play
Theaxial bearing shouldenablethe shaft torun
9/23freely duringthewholeturnandthereshould
notbe any axialplay.
Adjustment
Removethe cover plate5/13onthe underneath of
thebaseplate.Loosen the stop screws in the stop
ring.Then press the chain wheel inthedirectionof
thearrowandthestop ring in the opposite direction.
Tightenthestop screws.

15
The arm shaft circuit
The zig-zag movement
of the needle
Requirements
Theside movement oftheneedleshould not
commencuntiltheneedletipis5,5 mm above
thelevel ofthestitchplate.
Check
Firstcheck the height setting of the needle.
See page 22.
Turn onthemainswitch. Setthemachineat the
maximumstitch widthforzig-zag. Removethe
solefromtheholderandplace it on the stitch
plate.Slowlyturnthehandwheeluntiltheneedle
rises,observing the needle. Stop turningthe
handwheeljust astheneedlehas moved
sideways.Testwiththesole.Theneedle tip
shouldbe able to pass just over the highest
partofthe sole.
Adjustment
Loosenthe screw 7/44 in the screen and turn
thescreen until the correct needle clearance is
obtained.Theclearancewill increase if the
screenisturnedtowards the working direction
ofthe armshaft.

16
The needle bar frame
Thecenterpositionoftheneedleatright
anglesto thefeedingdirection.
Requirements
Theneedle shall be in the centreoftheneedle
holein the stitchplate.
Adjustment
Setthe needle at thehighestposition.Turnon
themain switch five-six times and check that
theneedlestopsatthesameposition (Control
ofthecalibrationofthestepmotor).Ifthisis not
the case, see page 36. If, it stopsat the same
position,turnthehandwheel untiltheneedle
eyeisatthesamelevelasthe stitch plate.
Removethe cassette andunscrewthescrew
(4/43),which holds thefrontpanelin place.
Pressthe front panel forwards and remove it.
Insertthe special screwdriver (Adamkey)
intothe opening for the threadtake-up
leverand loosen the setscrew(4/7).The
shaft(8/4) which supports theneedlebar
frameiseccentric.
Holdtheneedlebarin the feeding direction
andturntheshaft (8/4)carefully,by means
ofa screwdriver.Investigateif the required
needlepositioncanbeobtained.Ifso,fixthe
shaftwith stop screw (4/7).
Comments
Ifthe shaft (8/4)isshiftedaxially,thiswillaffect
theneedlepositioninthe feeding direction.
Iftherequiredneedle position cannot be obtained,
fixtheshaftatamiddlepositionandadjustthe
needlepositionasfollows:
Removethe rear cover.Fit the box spanner
411 1907-01 on the nut (8/30) and loosen the screw
(8/29)in thecentreof thenut.Turntheboxspanner
untiltherequiredneedlepositionisobtained.
Tightenthescrew.

17
The needle bar frame
Settingthe needle inthefeedingdirection.
Requirements
Theneedle should be centred in relationtothe
needlehole in the stitchplate.
Adjustment
Connectthe machineandturn on themainswitch,
Turn thehandwheeluntil theneedleis atthesame
levelas the stitch plate. Remove thecassetteand
unscrewthe screw(4/43)which holdsthefront
panelin place. Press the front panel forwards and
removeit. Insert the special screwdriver (Adam key)
4115844-01 into theopeningforthethreadtake-up
leverand loosen the stop screw(4/7)Theshaft(8/4)
whichsupports the needle bar frame canthenbe
shiftedfront to rear until the required needle position
isobtained. Retighten the shaft with thesetscrew(4/7).
Comment 1
Theshaft is eccentric and if turned, it affects
theneedlepositionatrightanglestothe
feedingdirection.
Comment 2
Thedistance between the centre oftheneedle
andthe shank varies with thesizeoftheneedle.
Inorder thatneedle120will not contactthefront
edgeoftheneedle slot, set the needle bar in
suchawaythatneedle (90) is in the middle of
theneedle slot. Needle(80)willthenbe slightly
behindthe centre of theneedlehole.
Needle 120
Needle 80
Stitchplate
Feeding direction

18
The stop, needle bar frame
Requirements
Thestop mustnotpreventthe needlereaching
thefull zig-zagbutshould stop theneedlefrom
goingoutsidetheneedle slot in the stitch plate.
Check and adjustment
Connectthe machineandturn on themain
switch.Turnthehandwheel untiltheneedle isat
thehighest position. Insert the servicecassette
andpress the key under 140,i.e. so that 5.0 is
indicatedin the digital window.Turn the
handwheel2-3revolutions.The needlewillmove
toa left-hand position, which isa cog division
outsidetheleftzig-zagposition.Setthestopin
thefaceplateby means of the screw (6/29) with
theleast possible play. Observethemovement
ofthe needle, press thebuttonforstraight
stitchingandsetthe left starting position. Check
thatthe needle bar frame has slight play against
thestop. Press the mirroring button and checkthe
right-handposition in a corresponding way.

19
The gap between the hook and the needle
Requirements
Removethe hookcover.
Connectthe machineandturn on themain
switch.Insert theserviceneedle No.
4115818-01 intothe needle bar. Lay the
machineonthetableonitsback.
Whenthetipofthehookisinfrontofthe
centreof the needle, asshowninthe
illustrationpress the hook against the
driver. The gap between the needle and
thehookshould be as small as possible.
Insertthesettingneedle No. 4115800-01
inthe needle bar and check that the hook
canpass. If the point of the hook contacts
the needle the gap is at max. See Fig 2.
Comments
Thehook comes into contact with the needle at point
A,picture3,i.e.thepartofthehookwhichisunderthe
tipof the hook, the so-called needle support.Thehook,
furthermore,is made in such a way that the top lies
appr. 0.05 mm in front of this needle support.
To enable the thread loop to go between the hook
andthedriver,according to illustration 4, a
certainaxial movement must be possible.
Contactbetween needle and hook can therefore
resultand this causes a sound, which canbe
heardif themachineisrunning withoutthread.
Thiscontact damages neither the hooknorthe
needle,as long as a needle witha groove
according to system 705 H is used.
Adjustment
Settingaccording to Requirements.
Turnthehandwheeluntilthe needleisatthe
highestposition.Theslotinthe driver is now in
themiddle, underneath thefeeddog.Undo the
Setting
needle
Gap
View B
Scale 2:1
threescrews (9/16) which holdthehook
cover-removerthe hook coverandthe hook.
Thenundo the threescrews(9/11)in thedriver,
(9/10)andremoveit.Thepositionofthe
driverisadjustedbyremoving or adding one
orseveralwashers (9/8). Note the position
ofthe slotinthedriver. Thencheck“The
gapbetween the driver and the hook cover”.
Spare parts: See RA, page 9!

20
Setting the timing of the hook in relation to the needle
Requirements
Connectthe machineandturn on themain
switch.As the needle is moving upwards the
tipofthehook should pass the centre of the
needlewhenthe needle is 2.5 mm above the
lowerturning position (the distancefor
formningthe loop).
Adjustment
Removethe cover (5/13) under the baseplate.
Thereare three screws on thepulley(9/27,28,29),
oneuntreated and twoblackones.Unscrew the
untreatedscrewand one of the black ones
completely, then loosen theotherblackscrewso
thatthe lowershaftisstill transportedwhenthe
handwheelisturned.
Turnthehandwheeluntilthe needleisatthe
lowerturning position. Place the setting gauge
4111752 on theneedlebar.Push the gauge
upuntil thespring-loadedstud just touchesthe
needlebar frame and tighten thescrew.Remove
thehookcover(9/15). Turn thehandwheelin the
samedirection as the machine is runninguntilthe
spring-loadedstudrests against its stop in the
gauge,according to the right-handfigure.The
needlehas now movedup2.5mm from the turning
position(thedistancefor forming the loop). Hold
thehandwheel fastandturn thehookandthe driver
sothatthetipofthehookcomesinfrontofthecentre
oftheneedle.Screwfastoneoftheblackscrews.
Turnthehandwheel intheoppositedirection until
theneedle returnstothelower turningposition.
Holdthehook back with one finger, so that it is
pusheddownwards and backwards,andturnthe
handwheelin the same direction as the machine
isrunning. When the studonthesettinggauge is
onceagain resting against its stop, the tip of the
hookshould be in thecentreoftheneedle. When
tighteningthescrewson thepulley,theuntreated
screw,whichisatippedscrew, should change
placeswith the black screw which wasunscrewed
earlier.Otherwisethereisariskthat the untreated
screwreturnstoitspreviousposition.Fitonthe
hookcover and the cover under the base plate.
Settinggauge
411 1752-01
Thelowerturning
pointof the needle
NOTE!
Thetip of the
hookat the
centreof the
needle.