Brother 434C Sewing Machine User Manual


 
8. ELECTRIC MECHANISM
KE-430B, 430C series
176
-14-. Problem solution and measures
1. Pay attention to the following when opening the control box for maintenance.
Electrical shock
Some large capacitors may have a high voltage remaining in them for up to 5 minutes after the power is
turned off. To prevent electrical shock, wait at least 5 minutes after the power is turned off before doing the
following:
• Opening and closing the control box
• Replacing fuses
• Separating and joining connectors
• Measuring resistance
• Doing anything with a possibility of touching something inside the control box
Some adjustments require measuring the voltage while the power is turned on with the control box kept open.
In such a case, be careful not to touch any place other than that for the measurement. In addition, always
keep in mind that a high voltage remains for about 5 minutes after power is turned off.
Injury
While the power is turned on, the cooling fan of the control box operates; be careful not to get caught in it.
When separating or rejoining connectors, and measuring something, be careful not to cut your fingers on
metal parts such as heat sinks and covers.
2. When replacing a fuse, be sure to use a new one of the same quality and capacity as the old one.
3. Refer to the circuit block diagram at the end of this manual regarding the connector numbers and their
matches.
Before adjustment
1. While the power is turned off, check each connector is securely plugged in by referring to “8-4. Connectors”.
2. Find the error status number in the troubleshooting flowchart.
3. From the applicable part of the flowchart, take the reference number to find the correspondingly numbered
details of the problem in the following table.