Brother BE-1204B Instruction Manual page 177

Symptom
The needle bar case lock error
occurs.
X-axis or Y-axis home position
detection error occurs.
The thread breakage error frequently
occurs although thread is not broken.
The X-axis motor connector
connection error occurs.
The main shaft motor lock error
occurs.
• Is the INDEX motor rotating?
→ If not, refer to the block diagram showing the cable connections and
check to see if connection from the INDEX motor to the main PCB
is proper.
Check the resistance values of pins 1 and 3 and pins 4 and 6 at the
connector section of the INDEX motor. The normal resistance
value is approximately 6.6Ω.
→ If it is not normal, replace the INDEX motor with a new one. Also
replace the drive PCB with a new one.
• Manually turn the color change pulley.
→ If it is abnormally heavy, adjust the color change mechanism and
the needle cap case.
• Replace the needle bar position sensor (potentiometer) with a new
one.
• Replace the I/O PCB 0 with a new one.
• Was the XY carriage moving?
→ If so, refer to the block diagram showing the cable connections and
check to see if connection from the X and Y area sensor to the drive
PCB is proper.
• Was the XY motor rotating?
→ If so, check the XY carriage mechanism.
• If the XY motor is not rotating, refer to the cable connection block
diagram and check to see if connection from the XY motor to the drive
PCB is proper.
• Enter the CASE test mode and turn the thread breakage sensor pulley
corresponding to each needle bar of the head with which this error
occurs while switching the needle bar from number 1 in ascending
order and check to see that the red LED on the head blinks.
→ If there is no problem, lower the thread breakage sensitivity value of
the machine controller. (The standard value is 0.)
• Check connection from the thread breakage sensor PCB to the thread
tension base PCB if it does not blink.
• Replace the thread breakage sensor PCB with a new one.
• Refer to the block diagram showing the cable connections and check
the connection from the two X motors (one X motors in four head
models) on the left and right to the main PCB.
• Enter the encoder signal mode and manually turn the main shaft pulley.
→ If it is abnormally heavy, the main shaft mechanism is faulty.
• Does the main shaft motor rotate at all when the error occurs?
→ If it does not rotate at all, check fuse F1 and F2 on the power supply
PCB in the control box. Refer to the block diagram showing the
cable connections and check to see if connection from the main
shaft motor to the drive PCB is proper.
• Manually turn the main shaft pulley in the encoder signal test mode
and check to see if the stop position signal and encoder signal are
proper.
→ If either of the signals does not change, refer to the block diagram
showing the cable connections and check to see if connection from
the encoder and stop position sensor to the power supply PCB is
proper.
BE-1204B-BC • BE-1206B-BC
Chapter 10 Troubleshooting
Measures
10-5