Brother S 7200 Manual

							 
 
S-7200A 
10. TROUBLESHOOTING 
35
10. TROUBLESHOOTING 
y Please check the following points before calling for repairs or service. 
y If the following remedies do not fix the problem, turn off the power switch and consult a qualified technician or the place of 
purchase. 
    DANGER 
 
Wait at least 5 minutes after turning off the power switch and disconnecting the power cord from the wall outlet 
before opening the face plate of the control box. Touching areas where high voltages are present can result in 
severe injury. 
 
     CAUTION 
 
Turn off the power switch and disconnect the power cord before carrying out troubleshooting. 
The machine may operate if the treadle is depressed by mistake, which could result in injury. 
 
10-1. Sewing 
Items with a “*” in the “Page” column should only be checked by a qualified technician. 
Problem Possible cause Page 
1  Upper thread is not tight. y Is the upper thread tension too weak, or is the lower thread tension 
too strong? 
Adjust the upper thread tension or lower thread tension. 
 
 
  
 
28 
2  Lower thread is not tight. y Is the lower thread tension too weak, or is the upper thread tension 
too strong? 
Adjust the lower thread tension or upper thread tension. 
 
 
  
 
28 
3  Loops appear in seam. y Is the thread path not smooth enough? 
Use a file with a fine grain or sandpaper to polish smooth the 
thread path. 
y Is the bobbin not turning smoothly? 
Pull out the lower thread to check that there is no slackness in 
the thread tension, or replace the bobbin or bobbin case. 
 
  
4 Skipped  stitches  occur 
while sewing y Is the needle tip bent? Is the needle tip blunt? 
If the needle tip is bent or broken, replace the needle. 
y Is the needle properly installed? 
If it is incorrect, install the needle correctly. 
y Is the machine properly threaded? 
If it is incorrect, thread the thread correctly. 
y Is the presser foot pressure too weak? 
Adjust the presser foot pressure. 
y Is the needle too thin? 
Replace the needle with a needle that is one rank thicker. 
y Is the presser foot too high? 
Adjust the height of the presser foot. 
y Is the thread take-up spring too weak? 
Adjust the tension of the thread take-up spring. 
 
  
 
 
13 
 
15 
 
29 
 
 
 
* 
 
* 
 
0573M
0574M
0977M
0470M 
						

							 
 
S-7200A 
10. TROUBLESHOOTING 
36
 
Problem Possible cause Page 
5  Skipped stitches at sewing 
start 
Thread unravelling at 
sewing start y Is the thread take-up spring tension too strong? 
Reduce the tension of the thread take-up spring. 
y Is the thread take-up spring operating range too large? 
Lower the position of the thread take-up spring. 
y Are the trailing lengths of the upper threads too short after thread 
trimming? 
Adjust the pretension. 
y Are the threads not being trimmed cleanly? 
Sharpen the fixed knives, or replace the fixed and movable 
knives if necessary. 
y Is the needle too wide? 
Try using a needle with a count that is one lower than the 
current needle. 
y Is the length of thread trailing out from the bobbin case after thread 
trimming too short. 
If the bobbin is spinning loosely, replace the anti-spin spring in 
the bobbin case. 
y Is the sewing speed too fast at the sewing start? 
Use the slow start feature. 
 
  
* 
 
* 
 
29 
 
 
* 
 
 
 
 
 
13 
 
* 
6 Uneven seam y Is the presser foot pressure too weak? 
Adjust the presser foot pressure. 
y Is the feed dog too low? 
Adjust the feed dog height. 
y Is the bobbin scratched? 
If the bobbin is damaged, smooth it with an oiled grindstone or 
replace it. 
 
  
29 
 
* 
 
 
 
7  Large degree of puckering 
(excess tension) y Is the upper thread tension too strong? 
Make the upper thread tension as weak as possible. 
y Is the lower thread tension too strong? 
Make the lower thread tension as weak as possible. 
y Are the thread take-up spring tensions too strong? 
Make the thread take-up spring tension as weak as possible. 
y Is the thread take-up spring operating range too large? 
Lower the position of the thread take-up spring to as low a 
position as possible. 
y Is the presser foot pressure too strong? 
Adjust the presser foot pressure. 
y Is the sewing speed too fast? 
Use the sewing speed control keys to gradually reduce the 
sewing speed. 
 
  
28 
 
28 
 
* 
 
 
* 
 
29 
 
 
18 
8 Material slippage y Is the presser foot pressure too strong? 
Adjust the presser foot pressure. 
 
 
 
 
 
 
 
  
29 
 
0749M
0473M
0978M
0750M 
						

							 
 
S-7200A 
10. TROUBLESHOOTING 
37
 
Problem Possible cause Page 
9  Lower thread is tangled at 
the sewing start. 
Spinning of bobbin during 
thread trimming y Is the bobbin spinning direction correct when the lower thread is 
being pulled? 
Set the bobbin so that it turns in the opposite direction to the 
rotary hook. 
y Is there too much thread 
wound onto the bobbin? 
The bobbin winding 
amount should not be 
more that 80 %. 
y Is 
the anti-spin spring attached? 
Attach the anti-spin spring. 
y Is the bobbin turning smoothly? 
If the bobbin is not turning smoothly, replace the bobbin. 
y Is a bobbin other that the light-alloy bobbins specified by Brother 
being used? 
Use only bobbins which are specified by Brother. 
 
  
 
 
14 
 
 
 
14 
 
13 
 
 
 
 
13 
10  Upper and lower threads 
are breaking. y Is the needle bent or is the needle tip broken? 
Replace the needle if it is bent or broken. 
y Is the needle properly installed? 
If it is incorrect, install the needle correctly. 
y Is the machine properly threaded? 
If it is incorrect, thread the thread correctly. 
y Is the rotary hook sufficiently lubricated? (-40[], 43[] specifications) 
If the oil gauge is down to the lower reference line in the oil 
gauge window, add more oil. 
y Is the upper or lower thread tension too weak or too strong? 
Adjust the upper thread or lower thread tension. 
y Is the upper thread may be loose because the thread take-up spring 
operating range is too small? 
Adjust the position of the thread take-up spring. 
y Is the rotary hook, feed dog or other part damaged? 
If they are damaged, smooth them with an oiled grindstone or 
replace the damaged parts. 
y Is the thread path damaged? 
If the thread path is damaged, smooth it with sandpaper or 
replace the damaged part. 
 
  
 
 
13 
 
15 
 
 
8 
 
28 
 
 
* 
 
 
* 
 
 
* 
11  Incorrect thread trimming 
(Upper and lower threads 
are both not being 
trimmed) y Is the fixed knife or movable knife damaged or worn? 
Replace the fixed knife or the movable knife. 
 
 
  
* 
12  Incorrect thread trimming 
(Upper thread or lower 
thread is not being 
trimmed) 
 y Is the needle properly installed? 
If it is incorrect, install the needle correctly. 
y Is the fixed knife or movable knife blunt? 
Replace the fixed knife or the movable knife. 
 
  
13 
 
* 
 
Lower  
thread
0751M
0471M2124M  
						

							 
 
S-7200A 
10. TROUBLESHOOTING 
38
 
Problem Possible cause Page 
13 Broken needles y Is the material being pushed or pulled with excessive force during 
sewing? 
y Is the needle properly installed? 
If it is incorrect, install the needle correctly. 
y Is the needle bent, is the needle tip broken, or is the needle hole 
blocked? 
Replace the needle. 
 
 
y It is extremely dangerous to leave any pieces of broken 
needle sticking in the material. If the needle breaks, search 
for all pieces until the whole of the needle is found again. 
y Furthermore, we recommend we recommend that through 
steps be taken to account for such needles to comply with 
product liability regulations. 
  
 
 
13 
 
 
 
14  Oil gauge (1) is not visible 
in oil gauge window. y Is the oil tank empty? 
(-40[], 43[] specifications) 
Fill the oil tank with oil. 
 
 
 
 
  
 
8 
15  Machine does not operate 
when power is turned on 
and treadle is pressed. y Is the power supply connector 
disconnected from the control 
box? 
Insert the connector 
securely. 
 
 
  
 
 
 
11 
16  Machine does not operate 
at high speed. y Is the sewing speed setting or backtack speed setting incorrect? 
Use the sewing speed control keys to set the high speed. 
  
18 
17 Machine stops during 
sewing. y Is the fixed stitch key turned on? 
Press the fixed stitch key so that the indicator turns off. 
y Is the power supply voltage too low? 
Check the power supply. 
(If the power cord is too long or too many appliances are being 
run from a single outlet, this may cause voltage drops which will 
in turn cause the reset function to activate and stop the 
machine, even if the power supply itself is normal.) 
  
18 
 
* 
18  Nothing appears on the 
operation panel display. y Is the power supply connector 
disconnected from the control 
box? 
Insert the connector 
securely. 
 
 
y Is the operation panel 
connector inside the control 
box disconnected? 
Insert the connector 
securely. 
 
 
  
 
 
 
11 
 
 
 
 
 
 
10* 
Caution
0469M
2195M
2196M 
2197M 
2196M  
						

							 
 
S-7200A 
10. TROUBLESHOOTING 
39
 
Problem Possible cause Page 
19  “GREASEUP” flashes on 
the operation panel when 
the power is turned on. y This display is to notify you that it is time to apply grease. 
Apply grease. 
 
  
33* 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
10-2. Error code displays 
If an error code appears on the operation panel display 
1.  Make a note of the error code and then turn off the power. 
2.  After the operation panel display has turned off, eliminate the cause of the error and then turn 
the power back on. 
 
 
Items with a “*” in the “Page” column should only be checked by a qualified technician. 
Error code Possible cause  Page 
Err    1 y Does the power supply voltage match the 
control box voltage specifications? 
Check the voltage. 
 
 
 
 
 
 
 
 
 
 
  
 
* 
Err    2 y Is the electrical equipment connector inside 
the control box disconnected? 
Insert the connector securely. 
 
 
 
 
 
  
 
* 
Err    3 
 y Is the encoder connector inside the control 
box disconnected? 
Insert the connector securely. 
 
 
 
 
 
  
 
10* 
2198M
2199M 
Voltage rating label 
2200M 
2201M  
						

							 
 
S-7200A 
10. TROUBLESHOOTING 
40
 
Error code Possible cause  Page 
Err    4 y Is the motor connector disconnected from the 
control box? 
Insert the connector securely. 
 
 
 
 
 
y Has the machine locked up? 
Turn off the power and then turn the machine pulley by hand and check that it 
turns easily. 
  
 
11 
Err    5 y Is the machine connector inside the control 
box disconnected? 
Insert the connector securely. 
 
 
 
 
y Is 
the machine head tilted back? 
Return the machine head to its normal position. 
  
 
10* 
Err    8 y This appears on the display when the sewing machine has been operating 
continuously for 3 minutes or more. 
Turn the power switch off and then back on again, and then operate the 
sewing machine normally. 
  
Err   13 y Is the treadle unit connector inside the control 
box disconnected? 
Insert the connector securely. 
 
 
 
 
 
  
 
* 
Err  100 
(GrEASEUP) 
y This appears on the display when the sewing machine has continued to be used for 
a certain period after the “GREASEUP” notification appears without the grease 
being applied (without the reset procedure being carried out). 
Apply grease and then carry out the reset procedure. 
  
 
 
33* 
Err  101 
(diP SW4)
 
y Is DIP switch No.4 inside the control box set 
to ON? 
Set DIP switch No.4 to OFF. 
 
 
 
 
 
 
 
  
 
* 
If an error code that is not listed above appears, contact the place of purchase. 
 
2203M 
2204M  2202M 
2205M  
						

							 
 
 
 
INSTRUCTION MANUAL       □ 
 
 
 
 
 
 
877-S20
SA2016-001
2003.02.B(1)