Download  Print this page

Brother LH4-B800E Service Manual Page 163

Electronic lockstitch button holer.
Hide thumbs

Advertisement

6. ELECTRIC MECHANISM
Code
<If E-07 occurs other than when machine is moving to the home position or starting>
1. Check if connector P11 on the main circuit board is securely inserted and if any harness is
broken or short-circuited.
2. Check the operation of the presser foot home position sensor monitor lamp.
- When the dog is nearby, the monitor lamp lights.
- When the dog moves away, the monitor lamp switches off.
* If the result of continuity test is not acceptable in either case, replace the presser foot home
position sensor.
E-07
3. If there is still an error even after replacing the presser foot home position sensor, replace the
main circuit board.
4. Check the sewing machine operation, particularly the operation of the upper thread trimming
mechanism, and eliminate the cause of the problem.
<If E-07 occurs when machine is starting>
1. Presser lifter pulse motor goes out of step during sewing machine operation.
Check the upper thread trimming mechanism, particularly for wear in the opening cam.
(Refer to "4-13-7. Adjusting the upper thread scissors gradual opening timing" and apply grease
to part C.)
1. Check if connector P7 on the sub circuit board is securely inserted and if any harness is
broken or short-circuited.
2. Check if connectors P23 on the main circuit board and P13 on the sub circuit board are securely
inserted and if any harness is broken or short-circuited.
3. Check the operation of the cutter home position sensor monitor lamp.
- When the dog is nearby, the monitor lamp lights.
E-08
- When the dog moves away, the monitor lamp switches off.
* If the result of continuity test is not acceptable in either case, replace the cutter home position
sensor.
4. If there is still an error even after replacing the cutter home position sensor, replace the sub
circuit board.
5. If there is still an error even after replacing the sub circuit board, replace the main circuit board.
1. With the power turned off, check for problems with feeding and check that the presser foot
moves smoothly.
2. Check if connectors P2 (feed) and P5 (presser foot) on the sub circuit board are securely
inserted and if any harness is broken or short-circuited.
E-20
* And also check if connectors P23 on the main circuit board and P13 on the sub circuit board
are securely inserted and if any harness is broken or short-circuited.
3. Replace the pulse motor that is malfunctioning.
4. Replace the sub circuit board.
1. With the power turned off, check if the zigzag mechanism moves smoothly.
2. Check if connector P16 (zigzag) on the main circuit board is securely inserted and if any harness
E-21
is broken or short-circuited.
3. Replace the zigzag pulse motor.
4. Replace the main circuit board.
1. Turn off treadle unit.
E-30
2. Check if connector P7 on the main circuit board is securely inserted and if any harness is broken
E-31
or short-circuited.
E-32
3. Replace the treadle unit.
4. If there is still an error even after replacing the treadle unit, replace the main circuit board.
1. Make sure that the control box is normally ventilated.
2. Clean the filter of the air intake. (Remove dust.)
E-40
3. Clean the cooling fan. (Remove dust.)
4. Make sure that the cooling fan is attached correctly.
1. Clean the inside air circulation cooling fan. (Remove dust.)
2. Check if connectors P13 and P20 on the main circuit board are securely inserted and if any
harness is broken or short-circuited.
3. Turn power off, check if connectors CN2, CN3 and CN4 on the 1-step power supply circuit board
E-41
are securely inserted and if any harness is broken or short-circuited.
* OK if 17 V AC is present between pins 4 and 5 of connector P20 on the main circuit board.
If not OK, replace the transformer.
4. Replace the cooling fan.
5. Replace the main circuit board.
6 - 30
Countermeasure
LH4-B800E

Advertisement

Table of Contents

   Also See for Brother LH4-B800E

   Related Manuals for Brother LH4-B800E

Comments to this Manuals

Symbols: 0
Latest comments: