Three Major Troubleshooting Methods for Computerized Needle Bar Components

The advent of various sewing equipment has brought significant economic benefits to clothing enterprises and improved the efficiency of operators. However, machine malfunctions seem to be an unavoidable issue. For computerized needle bar components, issues like power failure on startup, needle bar reversal, thread cutting, thread sweeping, and thread-cutting failures have long troubled operators. So, how can these three major faults be resolved?

First, when it is confirmed that the power plug is properly inserted, check whether the power switch is making good contact and whether the fuses on the power board are burnt out. If both of the above are fine, it may be that the 15W/20Q cement resistor on the power board is damaged. Simply replace it with a resistor of equivalent resistance. Line boards with lower resistance values are more prone to damage from high currents, while boards with higher resistance values may result in slow startup when powered on.

If one of these components is not functioning, such as the needle bar not reversing, first confirm whether the reverse sewing switch is turned on. Check if the electromagnetic coil is burnt out, whether the corresponding connectors are properly connected, whether the electromagnetic coil wire is worn out by the pulley, or if there is a fault in the needle bar reversal circuit on the control board. If the needle bar reversal switch is damaged or if none of the components for needle bar reversal, thread cutting, and thread sweeping are working: First, check whether the connectors for the computerized needle bar components are properly connected because most sewing machine brands design the connectors for these components to handle 30V.

When you hear that the thread cannot be cut, you may initially think that the cutting blade is dull. Even after replacing the cutting blade, if the thread still cannot be cut, you might suspect that the positioning of the thread cutting cam is incorrect, and no matter how much you adjust it, the problem persists. In reality, under normal circumstances, the cutting blade and fixed blade are not so easily dulled. The fixed blade of the computerized needle bar components in use for 2 to 3 years may not have required any maintenance.

From observations, in 80% of cases where a new machine cannot cut the thread, the reason is that the belt is too loose, or there are thread scraps wound around the motor wheel or handwheel, causing the belt to slip. This leads to the needle not stopping in the correct position. In severe cases, when the machine is supposed to cut the thread after stopping, the needle should be in the down position, but instead, it is above the needle plate. In this situation, the thread-cutting electromagnetic coil fails to engage with the thread-cutting cam follower, preventing the cutting blade from retracting, resulting in the machine's inability to cut the thread.