Brother RH-981A Service Manual page 134

Code
1. Check if the upper shaft motor wiring (U/V/W) is correct.
E-89 2. Check if connector P14 (UVW) on the control circuit board is inserted and that the harness-side
wiring is correct.
1. Check if connector P2 (MAIN) on the panel circuit board is securely inserted and if any connector is
broken or short-circuited.
2. Check if connector P18 (PANEL) on the control circuit board is securely inserted and if any
E-90
connector is broken or short-circuited.
3. Replace the panel circuit board with a new one.
4. Replace the control circuit board with a new one.
E-91 Refer to E70. (In input mode, check if the machine detects synchronizer signal.)
1. Make sure that power supply voltage is the same as the specification voltage.
2. If the conversion transformer is installed, check if terminals connections are correct.
3. Check if connector P20 (PER) on the control circuit board is securely inserted and if any harness is
broken or short-circuited.
E-92
4. Check if connector P2 (PER) on the power supply circuit board is securely inserted and if any
harness is broken or short-circuited.
5. Replace the power supply circuit board with a new one.
6. Replace the control circuit board with a new one.
1. Make sure that the large cooling fan is normally running.
2. Clean the large cooling fan. (Remove dust.)
3. Check if connector P10 (FAN-R) on the control circuit board is securely inserted and if any harness
E-93
is broken or short-circuited.
4. Replace the large cooling fan with a new one.
5. Replace the control circuit board with a new one.
1. Make sure that the small cooling fan is normally running.
2. Clean the small cooling fan. (Remove dust.)
3. Check if connector P25 (FAN-L) on the control circuit board is securely inserted and if any harness is
E-94
broken or short-circuited.
4. Replace the small cooling fan.
5. Replace the control circuit board with a new one.
1. With the power turned off, check if the feed bracket moves to the left and right.
2. Of the connectors relayed to the head harness, check if the connector for the X-axis pulse motor is
securely inserted and if any harness is broken or short-circuited.
E-95 3. Check if connector P7 (XPM) on the control circuit board is securely inserted and if any harness is
broken or short-circuited.
4. Replace the X-axis pulse motor with a new one.
5. Replace the control circuit board with new one.
1. With the power turned off, check if the feed bracket moves back and forth smoothly.
2. Of the connectors relayed to the head harness, check if the connector for the Y-axis pulse motor is
securely inserted and if any harness is broken or short-circuited.
3. Check if connector P6 (YPM) on the control circuit board is securely inserted and if any harness is
E-96
broken or short-circuited.
4. Replace the Y-axis pulse motor with a new one.
5. Replace the control circuit board with new one.
1. Make sure that the control box is normally ventilated.
2. Clean the filter of the air intake. (Remove dust.)
3. Clean the small and large cooling fans (Remove dust.)
4. Make sure that cooling fans are attached correctly.
E-97
• Large cooling fan: The wind blows toward the control circuit board and the PMD circuit board for
• Small cooling fan: The wind blows in the direction that it can discharge the air in the control box.
1. Check if connectors P12 (POWER) and P13 (DC55) on the control circuit board are securely
inserted and if any harness is broken and short-circuited.
2. Check if connector P1 (POWER) on the power supply circuit board is securely inserted and if any
harness is broken or short-circuited.
E-98
3. Check if connector P2 (DC55) on the PMD circuit board for θ-axis is securely inserted and if any
harness is broken or short-circuited.
4. Replace the power supply circuited board with a new one.
5. Replace the PMD circuit board for θ-axis with a new one.
6. Replace the control circuit board with a new one.
1. Refer to E95, E96 and E98.
E-99
2. Replace the power supply circuit board with a new one.
Countermeasure
θ-axis.
RH-981A
7. SOFTWARE
126