Bernina 740E - Manual (Page 50)

Trouble shooting guide AffeniKjH.
O$connecl rnacbne from otoceidty supply
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Upper ihread break«
Lower iivead break»
SkrppeO sMches
Neede break«
Loo«« stncrros
Seams gather or pucker
Uneven stitches, uneven feed
The machine is noojr
The rrtachne |em»
Cause
t. The macNne '» not threaded correcer
2. The thread tension >s юо dght
3. The ihrersd cs too thick tor the needle
<1 The tteade is not inserted correct^
S The ihtetMi
a rourd wound the «pool holder pm
6. The need« is damaged
t. The bobom case le not ineened correctly
2. The bobom case is threaded wrortgiy
3. The lower thread tension it loo l^hi
t The neede is not msonod oomcOy
2. The neede is damaged
3 The wrong size neodo has been used
4 The loot is not anached correctly
t. The needte Is damaged
2. The neede is not correcdy msorted
3 Wrong neerSe size tor the fabro
4 The wrong toot >8 attached
1. The machine « not correctly trreadt>d
2 The bobbin case is not conecPy threaded
3 Needle-labrtcilhread combmaten e wrong
4 Thread lenaon wrong
I The neodo is too thick lot the tabric
2. The stitch length « wrongly adiusteo
3 The thread tension it loo tight
I Poor quaMy ttiroad
2- The bobbin case « wrongly threaded
3 Pebric has been pullrxl
t The machine must be lubricated
2. rtutl or ol have cotiecied on the hoc* or neede bar
3 Poor диаЧу
0> has been used
4 The needle is damaged
I Thread is caught tn the hoc*
Correction
1 Rethread the machine 32
2 Reduce the tireed tension (tower number) 3<
3 Seed a larger needle 30
4 Remove and reinsert the r«ede (flat sbe towards the back) 28
5 Remove the reel and witvl dvead onto reel
6 Reptaca me needte
28
1 Remove and reinsert the bobbn case and put on the thread. The thread
shoiid p<4 eastly 26
2. Chet* both bobbm and bobbin case 26
3 Loosen lower thread tension as deserbed 26
1. Remove and remsen rteerSe {Rat sde towards the back) 28
2 insert a new neerRe 28
3 Cttoose a nee^ to sun the thread and tabnc 30
4 Chedr and attach oorteclly 22'tO
t Insert a new rteedle 28
2 been the needle conectly {hat s>de towards the back) 28
3 Choose a needle to sun the thread and fabr« 30
4 se-ect the correct toot 22rto
1. Check me threading 32
2 Thread the bobbin case as illustrated 26
3. The neede size must eutl the istnc and ihread 30
4 Correct the thread tensón 34
1 SeTecI a finer needle X
2 Read(u$i ire stiicn length
3 Loosen the thread tensón
34
1 Select a belter quality thread
2 Remove bobtxn case and remread and msert oorrectly 26
3 Oo not putt on the tabnc while smvng. W I be taken up by the macNne
1 Lubncaieasdescnbed 90
2 Clean me hook and leed dog as descrioed 90
3 Ody use good quality sewing machine oil 90
4 Replace the r>eede 28
1 Remo-ze the upper thread and boObm case, turn the nardwheei
backwards and forwards by hand and remove the tivead remants.
Lubricale as described 90
92