Dahao A15 Series Embroidery Machine Maintenance Guide

1. Needles high likelihood

How to tell

Skipped stitches, frayed thread, broken thread, damaged fabric, dull or bent needle points, burrs on the needle eye. Inspect needles visually for straightness and sharpness.

Fix

1. Turn off the machine power.
2. Loosen the needle clamp screw for the affected needle bar.
3. Remove the old needle.
4. Insert a new, correct size and type needle, ensuring the scarf is facing the rotary hook.
5. Push the needle up as far as it will go.
6. Tighten the needle clamp screw securely.
7. Perform a test stitch to confirm proper function.

Parts involved: Needles & needle bars →

2. Rotary Hook and Bobbin Case high likelihood

How to tell

Frequent thread breaks, poor stitch quality (looping, loose stitches), loud knocking noises from the hook area, burrs or nicks on the hook point or bobbin case. The hook point may appear dull or damaged.

Fix

1. Turn off the machine power.
2. Remove the needle plate and bobbin case.
3. Carefully inspect the rotary hook for any nicks, burrs, or wear on the point. Check the bobbin case for damage or lint buildup.
4. If minor burrs are present, they can sometimes be polished gently with very fine sandpaper (e.g., 600-grit or higher), but replacement is often best.
5. Clean the hook area thoroughly with a brush and compressed air.
6. If the hook or bobbin case is significantly worn or damaged, replace it with a new one.
7. Reinstall the bobbin case and needle plate, ensuring they are correctly seated.
8. Lubricate the rotary hook according to the manufacturer's manual.
9. Perform a test stitch.

Rotary hooks and bobbin cases are high-wear items and should be replaced as needed. Always have spares on hand.

Parts involved: Rotary hooks & bobbin cases →

3. Thread Tension Assemblies medium likelihood

How to tell

Inconsistent stitch quality, looping on top or bottom, thread breaks, difficulty adjusting tension. The tension discs may show grooves or wear from thread friction, or springs may lose tension.

Fix

1. Turn off the machine power.
2. Remove the tension assembly cover (if applicable).
3. Inspect tension discs for grooves, burrs, or embedded lint. Clean thoroughly with a brush or dental floss.
4. Check tension springs for proper compression and ensure they are not bent or damaged.
5. If discs are grooved or springs are weak, replace the affected components or the entire tension assembly.
6. Reassemble and test tension settings with new thread.

Individual tension disc sets or complete tension assemblies may need replacement.

Parts involved: Thread path & tension →

4. Thread Trimmer/Cutter Blades medium likelihood

How to tell

Uncut threads, frayed thread ends after trimming, partial cuts, or loud noises during trimming. Blades may appear dull, chipped, or misaligned.

Fix

1. Turn off the machine power and unplug it.
2. Access the trimmer mechanism (refer to your machine's manual for specific location).
3. Carefully inspect the stationary and moving blades for dullness, nicks, or damage.
4. Clean any lint or debris from the trimmer area.
5. If blades are dull or damaged, replace both the stationary and moving blades as a set.
6. Ensure new blades are installed correctly and aligned according to the manual.
7. Test the trimming function with various thread types.

Trimmer blades are precision parts and should be replaced as a set when worn.

Parts involved: Cutters & trimmers →

5. Drive Belts (X/Y Axis, Head Drive) medium likelihood

How to tell

Skipped stitches, misaligned embroidery, jerky movement of the pantograph or head, squeaking noises, visible cracks, fraying, or stretching on the belts. Loose belts can cause backlash.

Fix

1. Turn off the machine power and unplug it.
2. Locate the drive belts (X-axis, Y-axis, and head drive belts).
3. Inspect belts for signs of wear, cracking, fraying, or excessive looseness.
4. If a belt is worn, carefully remove it by loosening tensioners or idler pulleys.
5. Install a new belt, ensuring it is the correct size and type.
6. Adjust belt tension according to the manufacturer's specifications (do not overtighten).
7. Manually move the pantograph/head to check for smooth movement.
8. Perform a test embroidery to verify accuracy.

Belts should be replaced if they show any signs of wear or stretching. Keep spare belts for critical drives.

Parts involved: Belts, pulleys & gears →

6. Solenoids (e.g., Thread Break Sensor, Needle Bar Selector) low likelihood

How to tell

Specific functions failing (e.g., thread break not detecting, needle bar not selecting correctly), clicking but no action, or no clicking sound at all. Solenoids can become weak or seize.

Fix

1. Turn off the machine power and unplug it.
2. Identify the faulty solenoid (often requires diagnostic testing or observing the specific malfunction).
3. Disconnect wiring to the solenoid.
4. Unscrew and remove the old solenoid.
5. Install a new solenoid, ensuring proper orientation and secure mounting.
6. Reconnect wiring.
7. Test the associated function.

While less frequent, solenoids can fail due to mechanical fatigue or electrical issues. Specific Dahao A15 solenoids may be available.

Parts involved: Solenoids & magnets →

7. DAHAO EF119 12-Needle Decoding Plate / DAHAO EF139 12-Needle Decoder Board low likelihood

How to tell

Incorrect needle selection, machine not recognizing specific needles, error codes related to needle decoding, or intermittent needle selection issues. Often accompanied by other electronic issues.

Fix

1. Turn off the machine power and unplug it.
2. Locate the decoding plate/decoder board (refer to your machine's manual).
3. Carefully disconnect all ribbon cables and power connectors.
4. Unscrew and remove the old board.
5. Install the new DAHAO EF119 12-Needle Decoding Plate or DAHAO EF139 12-Needle Decoder Board, ensuring all connections are secure and correctly oriented.
6. Power on the machine and test needle selection functionality.
7. If issues persist, further diagnostics may be needed for other electronic components.

These boards are critical for needle selection. Ensure proper handling to avoid static discharge.

Parts involved: Circuit boards & electronics →