---
title: "Melco Embroidery Machine Troubleshooting: Melco OS Errors, Thread Breaks and Fixes"
description: "Melco machine troubleshooting with Melco OS error messages, keypad lights, thread breaks, missed trims and maintenance for EMT16X, SUMMIT, Bravo, Amaya."
url: https://easydigitizer.com/troubleshooter/melco
updated: 2026-10-14
brand: Melco
class: commercial
origin: USA
formats: EXP (native), OFM (native), DST, ARTX
data: https://easydigitizer.com/troubleshooter/data.json
agent_playbook: https://easydigitizer.com/troubleshooter/agent.md
publisher: EasyDigitizer (https://easydigitizer.com/)
---

# Melco embroidery machine troubleshooting

Melco machine troubleshooting with Melco OS error messages, keypad lights, thread breaks, missed trims and maintenance for EMT16X, SUMMIT, Bravo, Amaya.

> **Short answer:** Most Melco stops come from three things: a thread bind or birdnest under the needle plate, bobbin tension outside the 250–300 gauge range, and an out-of-date Melco OS. Clear the bind, check the bobbin case on a gauge, and update the software before you chase anything else. The error you will see most is a **Z timeout / Z tracking** or **color change timeout**, and both usually trace back to thread wrapped in the hook area.

## Model families
### EMT16X
- **Type:** Commercial single-head, modular (link up to 30 heads over Ethernet), 16 needles
- **Years:** Current
- **Field:** 41 × 39.3 cm flats; 36 × 8.1 cm with the wide-angle cap frame
- **Max speed:** 1,500 spm flats, 1,200 spm caps
- **Panel:** External PC running Melco OS v11 (Simplified UI or Advanced Interface) plus keypad
- **Formats:** EXP, DST, ARTX, OFM
- **Manual:** [EMT16X support page (operator, technical and parts manuals)](https://www.melco-service.com/emt16x.html)
- **Tags:** modular, cap, 16-needle, Acti-Feed, laser, NPT trimmer
Melco's current workhorse. It has Acti-Feed automatic thread feed instead of tension knobs, so "tension" problems are usually Acti-Feed settings, the bobbin, or the thread path. The NPT needle-plate trimmer gives its own family of errors (selector timeout, unable to home trimmer, needle plate not installed correctly).

### SUMMIT
- **Type:** Commercial single-head, 16 needles
- **Years:** Current
- **Field:** 41 × 39.3 cm flats; 36 × 8.1 cm caps
- **Max speed:** 1,500 spm flats, 1,200 spm caps
- **Panel:** Built-in 10.1 in. HD touchscreen, built-in QR/barcode reader, Wi-Fi or LAN
- **Formats:** EXP (with colour INI), DST, ARTX, OFM
- **Manual:** [SUMMIT support page (operator, technical and parts manuals)](https://www.melco-service.com/summit.html)
- **Tags:** touchscreen, cap, 16-needle, Acti-Feed, laser, network folder
Same sewing head size and speed as the EMT16X but with the controller built in, so no separate PC. Melco documents "Thread in Cloth" and "Z Hall Error" touchscreen messages for this model; both are usually fixed by reseating the needle plate assembly.

### EMT16 Plus and EMT16
- **Type:** Commercial single-head, modular, 16 needles
- **Years:** Discontinued (still widely used)
- **Panel:** External PC running Melco OS (older units: AMAYA OS) plus keypad
- **Formats:** EXP, OFM, DST
- **Manual:** [Melco service site, machine manuals](https://www.melco-service.com/)
- **Tags:** modular, cap, 16-needle, Acti-Feed
The predecessors of the EMT16X. Common failure points are a damaged S95 cutter, loose cutter blade screws, and using the old bobbin case (PN 34396) instead of the recommended PN 004267-01.

### Bravo (Bravo, Bravo 2, Bravo X)
- **Type:** Commercial single-head, 16 needles
- **Years:** Bravo and Bravo 2 discontinued; Bravo X is the later version
- **Field:** 32 × 26 cm flats; 15.2 × 8.1 cm caps
- **Max speed:** 1,000 spm
- **Panel:** External PC running Bravo OS
- **Formats:** EXP, DST, ARTX, OFM
- **Manual:** [Melco service site, Bravo pages](https://www.melco-service.com/)
- **Tags:** entry-level, cap, 16-needle, Acti-Feed
A lighter, non-modular machine on a composite base. "Axis error" with a loud noise is usually an X cable that needs re-tensioning.

### Amaya XT and XTS
- **Type:** Commercial single-head, modular, 16 needles
- **Years:** Discontinued
- **Panel:** External PC running AMAYA OS v9/v10 or Melco OS v11
- **Formats:** EXP, OFM, DST
- **Manual:** [Amaya XT/XTS manuals (Amaya UK, Melco distributor)](https://help.amayauk.com/melco)
- **Tags:** modular, cap, 16-needle, Acti-Feed
Older modular machines. Axis errors, X cable tension and Windows driver-signing problems with the old AMAYA OS network driver are the usual complaints.

### Original AMAYA ("Big Red", non-XT)
- **Type:** Commercial single-head, 16 needles
- **Years:** Discontinued
- **Panel:** External PC running AMAYA OS
- **Formats:** EXP, OFM, DST
- **Manual:** [Amaya non-XT technical and parts manuals (Amaya UK)](https://help.amayauk.com/melco)
- **Tags:** legacy, 16-needle
The original red Amaya. Melco lists several faults that only occur here: color change timeout, off-index while sewing and "error trying to read ALTERA". The colour-change home sensor is discontinued, so a failed sensor may need to be spliced by a technician.

### Legacy EMC, EMT, EMB and EP1 machines
- **Type:** Older Melco commercial machines
- **Years:** Discontinued
- **Manual:** [Melco service site, legacy machine pages](https://www.melco-service.com/)
- **Tags:** legacy
Melco still hosts manuals for these older machines on its service site. Their status messages differ from Melco OS and are not listed in the table below; use the symptom guides and the legacy manual for your model.

## Error codes
| Code | Message | Meaning | Fix | Models | Source |
|---|---|---|---|---|---|
| X/Y timeout | X / Y motor timeout or tracking error | The pantograph could not reach the commanded position in time. Often a one-off; if it repeats, something is physically blocking the hoop. | Press and release the E-stop, then press green Start. If it returns, look for a garment caught under the arms or against the machine and free it, then repeat. | EMT16X, EMT16 Plus, Amaya | Amaya UK help centre (dealer) |
| X over current | X motor over current | The X motor is drawing too much current, almost always because something binds the X travel. | Remove the hoop or cap driver and power cycle. If the error clears, find the bind (hoop, driver, clamp, lower arm, X cable, pulleys). If not, have a tech check X cable tension and the ribbon cable or reflash the main PCB. | EMT16X, EMT16 Plus | Melco KB |
| Axis error | Axis error (with loud noise) | The X axis is slipping or binding, usually from a loose or worn X cable. | Stop sewing. Re-tension the X cable following Melco's procedure, or book a certified technician. | Amaya XT, XTS, Bravo | Melco KB |
| Z timeout | Z axis tracking error / Z timeout | The needle drive could not complete its stroke. Causes: thread bind in the hook, bobbin tension wrong, stitches too tight or too little thread fed, poorly hooped caps, dry or dirty hook, outdated software. | Clear any thread wrapped under the needle plate, check bobbin tension on a gauge, rehoop caps tightly, clean and oil the hook, update Melco OS. If it persists, have a tech check the selector home cable on the trimmer board. | All Melco OS machines | Melco KB |
| MOVETOORIGION | MOVETOORIGION Failed | The machine could not return to origin, usually because a needle is stuck down after the 30-million-stitch maintenance. | Follow the needle stuck / Z bind steps from the 30M maintenance guide to free the needle bar, then power cycle. Call support if it stays. | EMT16X, EMT16 Plus | Melco KB |
| Color change timeout | Color change timeout | The needle case did not move during a colour change. | Delete the Jobs and Machines folders, power cycle, and check by hand that the case sits on a needle with the head up. On original Amaya, check the home sensor and motor. Other models: call Melco support. | All (detailed steps for original Amaya) | Melco KB |
| Stepper index error | Color change stepper index error / seek error | The needle case could not shift left or right correctly. | Check the log, confirm trimmer type and machine type in settings, run Set Table and check thread-feed drive gear alignment. Replace the thread feed motor if homing cannot line up the gears (technician). | EMT16X, EMT16 Plus, Amaya | Melco KB |
| Off index | Color change stepper index error, off index while sewing | The needle case drifted off index during sewing. | Follow the colour change stepper index steps for original Amaya: power cycle and make sure the presser foot is not stuck between needles. | Original Amaya | Melco KB |
| ALTERA | Error trying to read ALTERA on motor drive PCB | On original Amaya, the colour change is not on index or the case is misaligned. | Check that Index reads Open with the needle at head up. If not, push the case by hand until the presser foot centres on a needle, then cycle the E-stop. | Original Amaya | Melco KB |
| Stepper status | Error trying to read stepper motor status | The software could not read the stepper drives; the pantograph may not move. | Delete the Jobs and Machines folders, power cycle, look for related errors such as X motor home timeout, and refresh the software registry. Then check the colour change motor. | Melco OS machines | Melco KB |
| Grabber index | Grabber stepper index error | The thread grabber bar did not move as expected. | Close any open menu, then toggle the grabber out from the software. Call support if it repeats. | EMT16X | Melco KB |
| Selector timeout | Selector timeout trying to find home position | The NPT trimmer knife did not move back to home. | Clear the error, remove the needle plate, power cycle, then home the knife and connecting link. Reseat the K2, J63 and general RFU harnesses (technician if unsure). | EMT16X | Melco KB |
| Trimmer home | Unable to home trimmer | The trimmer knife did not move as expected. | Remove the needle plate, power cycle and home the knife. Look in the log and under the plate for a broken needle jamming the blade. | EMT16X, SUMMIT | Melco KB |
| Thread feeder timeout | Thread feeder timeout trying to find home position | The Acti-Feed motor could not find home: thread caught in the feed housing, dirty sensor, worn motor or misaligned gears. | Power cycle and update. Remove caught thread from the feed housing, check the lower pinch roller spins freely, clean the optical sensor. If the gear flag does not read correctly, have a tech check the motor and gear mesh. | Acti-Feed machines | Melco KB |
| Needle position 0 | Needle Position is at 0 | The colour change / thread feed home sensor is not reading correctly. | Cycle the E-stop and home the colour change steppers. Spin the lower pinch roller and test the feed home sensor. Check for Z bind. The thread feed motor may need replacing. | EMT16X, EMT16 Plus | Melco KB |
| Needle plate (knife) | Needle plate is not installed correctly (remove plate, put knife at far back, reinstall) | The plate is not seated or the NPT knife is not fully back. | Remove the needle plate, push the knife to the far-back position, and reinstall it firmly. If the message loops, change the 2-million-stitch timer step in the Advanced settings. | EMT16X | Melco KB |
| Needle plate (2M) | Needle plate is not installed correctly, remove the needle plate before proceeding | The plate sensor read unexpected values during the 2M-stitch maintenance wizard. | Update Melco OS, remove the plate, continue the wizard past the plate step, then home the NPT knife. | EMT16X | Melco KB |
| Thread in Cloth / Z Hall | Thread in Cloth, or Z Hall Error (touchscreen) | The needle plate assembly is not seated correctly. | Remove and reinstall the needle plate assembly following Melco's NPT removal steps. | SUMMIT, Bernina E16 PRO | Melco KB |
| Cycling | --Cycling-- initializing machine - please wait (never finishes) | The machine never finishes start-up: wrong software for the model, an axis bind or a communication fault. | Confirm you run the right software (Melco OS vs Bravo OS), power cycle, look for X, Y or Z binds and check the trimmer type. If the machine shows as "No Name", run the beep test and call support. | Melco OS, Bravo OS | Melco KB |
| Start beeps | Start button beeps once, machine does not sew | Something is blocking start: E-stop engaged, bobbin timer, colour sequence problem, Z bind or a bad button. | Release the E-stop, clear and reassign the colour sequence, turn off the bobbin timer, check for a Z bind, then power cycle. | EMT16 family, Bravo | Melco KB |
| Too large | Design is too large for machine(s) | The design exceeds the machine's limits. Older main PCBs accept under about 130,000 stitches and 99 colour changes. | Reset the design and reload. Turn off other linked machines or try another PC. Split very large designs and note the X/Y offset of each half. | Melco OS machines | Melco KB |
| Design rejected | Design rejected: Machine busy or file is too big | The machine is still busy or the file is too large. | Reset the design and reload; split oversize designs. | Melco OS machines | Melco KB |
| Load failed | Loading Design to Machine Failed. Invalid design file or file too large to load | The stored stitch count must be reset. | Switch to the Advanced OS, press Reset Design and Center Hoop, switch back to the Simplified UI and load again. | EMT16X (Simplified UI) | Melco KB |
| Load denied | Design load denied. Machine is currently in the middle of a design | A previous design is still active on the machine. | Use Return to Origin or Reset Design, then load. Power cycle if it persists. | Melco OS machines | Melco KB |
| MC_COMMTIMEOUT | Design download failure, CmdStatus = MC_COMMTIMEOUT | The PC could not send the design. | Power off the machine, close Melco OS, delete the Jobs folder, restart both, reset and reload the design. | Melco OS machines | Melco KB |
| Download denied | Design download denied | Communication failed between PC and machine. | Check for a Z bind and the Ethernet cable, then power cycle with the needle plate removed. | Melco OS machines | Melco KB |
| Display design | Melco OS is not able to correctly display the design that is currently loaded | The OS lost track of the last design. | Reload the design or press Reset Design; power cycle if the machine dropped off; try another design. | Melco OS | Melco KB |
| Improper argument | Encountered an Improper Argument (sending from DesignShop to Melco OS) | A problem inside that design file, often an auto-digitized one. | Re-digitize or clean up the design; other designs should load normally. | Melco OS, DesignShop | Melco KB |
| Hoop limit (WACF) | Hoop Limit Detected (wide-angle cap frame, Melco OS v11.21.67) | The hoop database wrongly rejects designs that fit the WACF. | Install the corrected hoop database file from Melco, or send the design from DesignShop with the WACF hoop selected. | Melco OS v11.21.67 | Melco KB |
| Hoop limit (sequin) | Hoop limit detected for sequin device | The design contains a sequin eject command. | Delete the sequin element from the design and reload it. | Melco OS | Melco KB |
| Hoop change | HOOP CHANGE FAILED | The hoops database is out of date. | Update the hoops database from Melco. | Melco OS | Melco KB |
| Out of Memory | Out of Memory | The file is not a proper OFM or the design is corrupt. | Copy the design to the desktop, save it as EXP, delete the Jobs and Machines folders if the OS crashes, or re-digitize the design. | Melco OS | Melco KB |
| Integer -40..40 | Enter an integer between -40 and 40 | An out-of-range value in a colour or thread feed setting. | Restore Thread Feed defaults under Color Sequence, then reset the thread break sensor (TBS) in Settings if offered. | Melco OS | Melco KB |
| Ethernet start | Ethernet communications did not start correctly, restart computer | Melco OS cannot detect the machine, often after a Windows update. | Turn off Compatibility Mode, run Melco OS as Administrator, then follow the machine-not-detected steps. | Melco OS | Melco KB |
| Connection failed | Machine connection was unsuccessful | The machine is not talking to the PC. | Switch to the Advanced OS, resend the design, run as Administrator and follow machine-not-detected steps. | EMT16X | Melco KB |
| CSA/RSA mismatch | The version of the CSA (or RSA) program in the machine and the version of the file in the computer do not match | Machine firmware and PC files differ. | Turn the machine off, tick Force Download under Tools > Options > Ethernet, turn the machine on. Reset the main PCB if it continues. | Melco OS | Melco KB |
| Type/serial conflict | Machine type and serial number conflict, reconfigure the machine | Several machines are connected to a single-machine (Lite) software level, or the dongle is not seen. | Connect one machine only, or fix the USB security dongle so the full licence is read. | Melco OS | Melco KB |
| Incorrect path | [Filename] Contains an Incorrect Path | Invalid machine name or serial number, or wrong database path for barcodes. | Set a valid machine name and S/N under Tools, and check the database path. | Melco OS | Melco KB |
| Settings read | AMAYA OS has detected a serious error reading the current settings from the machine | The OS could not read the machine's settings. | Restart the software; on older boards press the reset button; power on one machine at a time. | AMAYA OS | Melco KB |
| Bad Image | "Bad Image" when opening Melco OS, Bravo OS or DesignShop | A Windows or antivirus update damaged the install. | Uninstall and reinstall the latest version; turn off Smart App Control and Compatibility Mode. | Melco OS, Bravo OS | Melco KB |
| Driver blocked | The driver has been blocked (PcaSp60.sys or AMAYASp50x64.sys) | A Windows 11 update blocks the old network driver, so the machine adapter disappears. | Install the updated driver package (AMAYA OS v10.01.001) or ask Melco support about driver signature enforcement. | AMAYA OS, older Melco OS | Melco KB |
| App blocked | This app has been blocked for your protection | Windows blocks older DesignShop v9 / AMAYA OS v9–v10. | Follow Melco's unblock steps or move to a current OS version. | AMAYA OS v9, v10 | Melco KB, Amaya UK |
| USB dongle | USB device not recognized | Windows cannot read the Melco USB security dongle. | Follow Melco's "USB security dongle not recognized" steps; try another port. | Melco OS | Melco KB |
| Red slow blink | Keypad light red, blinking slowly | Upper thread break. | Rethread the needle that stopped and restart. | Keypad machines | Melco KB |
| Red fast blink | Keypad light red, blinking fast | Bobbin is empty or the bobbin thread broke. | Replace the bobbin or fix the break, then restart. | Keypad machines | Melco KB |
| Red solid | Keypad light red, steady | E-stop pressed, or the sequin device is switched on. | Release the E-stop; turn off the sequin device with Stop + Laser + Frame Back together. | Keypad machines | Melco KB |
| Green 2s/0.5s | Keypad light green, on 2 s, off 0.5 s | Low-power sleep mode. | Hold Start 3 s to wake. | Keypad machines | Melco KB |
| Green 1s blink | Keypad light green, blinking once a second | The machine needs its RSA/CSA files (main board 31058-19 or older). | Release the E-stop, tick Force Download and power cycle. | Older keypad machines | Melco KB |
| Red/green alt | Keypad red and green alternating | Not a user-fixable state. | Call Melco technical support. | Keypad machines | Melco KB |

## Common problems and fixes
### Upper thread keeps breaking
**Symptoms:** thread, needle, tension
**Likely causes:** burred or backwards needle, thread snagging in the path or cone, too much spray adhesive, damaged hook or cutter, Acti-Feed settings
1. Change the needle. Seat it fully up, with the groove to the front and the eye turned about 5° to the right (anywhere from 0° to 20° right is OK; any left turn is wrong).
2. Rethread that needle from the cone, making sure the thread wraps around the thread break bar and sits in every guide.
3. Check the cone: the thread tube should stand about ½–1 in. above the cone, and the cone should feed freely.
4. Wipe off spray adhesive build-up on the needle and plate, and use less spray.
5. Check the bobbin tension (250–300 on the Melco gauge) and the Acti-Feed settings for this fabric.
6. Inspect the hook point and cutter for burrs.
**Call a technician if:** breaks continue with a new needle, clean path and correct bobbin, which points to hook timing or needle depth.

### False thread breaks (machine stops but the thread is fine)
**Symptoms:** sensor, thread
**Likely causes:** thread not around the break bar, wrong bobbin tension, Acti-Feed lower limit too high, sensitivity setting
1. Rethread and confirm the thread goes around the thread break bar.
2. Check bobbin tension on the gauge.
3. Check the Acti-Feed lower limit is not raised above the default (4 points).
4. Reset the thread break sensitivity to default (0), then raise it one step at a time if false stops continue.
5. Update Melco OS.
**Call a technician if:** a sensor foam washer has fallen off or one needle always false-stops after the steps above.

### Thread breaks are not detected (machine sews on with no thread)
**Symptoms:** sensor, thread
**Likely causes:** sensitivity set too low, thread detection disabled
1. Make sure bobbin and upper thread detection are enabled in the settings.
2. Run the thread break sensor test on needles 1, 9 and 16.
3. If breaks are missed, set TBS sensitivity to -10, then step it up only if false breaks start.
**Call a technician if:** the test fails on one needle with all settings correct.

### Birdnest under the needle plate
**Symptoms:** birdnest, bobbin, thread
**Likely causes:** upper thread out of the tension path, bobbin problems, flagging fabric
1. Stop the machine. Never pull the hoop to free it.
2. Cut the threads between the garment and the needle plate, then remove the hoop.
3. Remove the needle plate and clean all thread out of the bobbin and hook area.
4. Inspect the knife, oil the hook, recentre and refit the needle plate.
5. Reinsert the bobbin, rehoop and check the whole upper thread path before restarting.
**Call a technician if:** birdnests keep returning with a clean hook and correct bobbin tension.

### Needles keep breaking (especially on caps)
**Symptoms:** needle, cap
**Likely causes:** needle deflection on buckram, centre seams or the visor; needle too thin; worn needle; bent presser foot; cap not clamped
1. Use a sharp, larger needle on structured caps; 85/13 is often a good start. Avoid sizes under 75/11 on caps.
2. Make sure the cap is held by all three clamps and none are bent.
3. Set the presser foot to the cap, then go down one click after it touches. For 3D puff, raise it to the last (9th) click.
4. Replace chrome needles every 4–8 sewing hours. Titanium lasts longer but snaps rather than bends.
5. Check for a Z bind.
**Call a technician if:** needles hit the plate or hook, which means needle depth or hook timing is off.

### Machine is not trimming or misses trims
**Symptoms:** trimmer
**Likely causes:** no tie-in or tie-off before the trim, wrong bobbin tension, retaining finger out of adjustment, dull knife, trimmer not homed
1. Check the design has tie-ins and tie-offs and enough stitches between trims.
2. Check bobbin tension on the gauge.
3. On the EMT16X, home the knife and run the trim test from the maintenance menu.
4. On the EMT16 and EMT16 Plus, check the cutter blade screws are tight and the S95 cutter is not damaged.
5. Do the rotary hook maintenance and check the retaining finger.
**Call a technician if:** the knife is worn, the trimmer setup is wrong or a re-flash of the main PCB is needed.

### Z timeout or Z tracking errors
**Symptoms:** timing, birdnest, motor
**Likely causes:** thread wrapped in the hook, bobbin tension wrong, stitches pulled too tight, loose cap, dry hook
1. Remove the needle plate and clear any thread in the hook.
2. Check bobbin tension and the Acti-Feed setting (too little thread fed makes stitches bind).
3. Rehoop caps tightly and confirm the cap driver is set correctly.
4. Clean and oil the hook, then update Melco OS.
**Call a technician if:** the error returns on a clean machine; the selector cable or hook timing may need attention.

### Color change timeout or needle case won't move
**Symptoms:** colour-change, motor
**Likely causes:** birdnest pulling on the needles, presser foot caught between needles, gear misalignment, sensor
1. Clear any birdnest; thread binds commonly cause colour-change seek errors.
2. Check by hand that the needle case sits on a needle with the head up.
3. Delete the Jobs and Machines folders and power cycle.
4. Confirm machine type and trimmer type in settings and run Set Table.
**Call a technician if:** the case still will not index or the colour-change motor or sensor is suspect.

### X/Y errors, axis noise or circles sewing as ovals
**Symptoms:** frame, registration, noise
**Likely causes:** garment trapped, X cable tension wrong, cap driver set wrong, fabric shifting
1. Free any garment caught under the arms and restart.
2. Remove the hoop or cap driver and power cycle; if the error goes away, find the bind.
3. Check the wide-angle cap driver height: a business card should just fit between the needle plate and driver ring.
4. If shapes distort but there is no error, it is usually fabric movement: hoop tighter, use better backing, and add pull compensation in the design.
**Call a technician if:** the X cable is frayed or needs tensioning; Melco says only certified technicians should replace it.

### Design won't load or the machine isn't detected
**Symptoms:** file, network, usb
**Likely causes:** Windows update, missing administrator rights, old design still active, design too big, dongle not read
1. Run Melco OS as Administrator and turn off Compatibility Mode.
2. Press Reset Design (or Return to Origin) and reload.
3. Delete the Jobs folder and power cycle machine and PC.
4. Save the design as OFM or EXP and split very large designs.
5. Check the USB security dongle is recognised.
**Call a technician if:** the machine is never detected on a known-good cable and PC.

### Bobbin runs out early or looks bad on top
**Symptoms:** bobbin, tension, looping
**Likely causes:** bobbin tension too loose, wrong or dirty bobbin case
1. Clean the bobbin case and check it on the Melco gauge: 250–300, steady while pulling about 1 in. per second.
2. Replace the case if the reading jumps around.
3. On EMT16 machines, use the recommended case PN 004267-01, not the early PN 34396.
**Call a technician if:** a new case still gives unstable readings.

## Maintenance schedule
| Interval | Task | Notes |
|---|---|---|
| Start of day and every 4 hours of sewing | Clean and oil the rotary hook | Use the hook oiler pen with Melco machine oil. WD-40 can clean but must never be used as lubricant. |
| Daily | Rotary hook maintenance and lint removal | Clean under the needle plate more often on towels, fleece and other high-lint goods. Keep covers dust free. |
| Every 4–8 sewing hours | Replace needles | Chrome needles; titanium lasts about 2–3 times longer. |
| 2 million stitches (about weekly) | 2M maintenance from the Melco OS timer | Follow the on-screen step-by-step guide (Tools > Maintenance). |
| 10 million stitches (about monthly) | 10M maintenance | Includes red SHC grease on the eccentric, Y rail lubrication and X beam / X cable checks. |
| 30 million stitches (about quarterly) | 30M maintenance | Follow the on-screen guide; if a needle sticks down afterwards, use the needle stuck / Z bind procedure. |
| When servicing the thread feeder | Grease plastic feed rollers | Beige polymer grease on plastic parts only, never on metal; red grease is not used here. |

## Settings that cause stitch problems
- **Thread break sensitivity:** current Melco OS uses -10 to 10, default 0; older versions (Melco OS v11.11.114, Bravo OS v12.02.122 and earlier) use -100 to 50 in steps of 10. Too low misses breaks; too high gives false stops. Change one step at a time.
- **Backup after a thread break:** the machine backs up at most 10 stitches for an upper break and 17 for a bobbin break, so check the repair overlaps.
- **Acti-Feed:** this replaces tension knobs. Caps need a higher setting than most flats. A lower limit raised above the 4-point default causes false thread breaks. Run Melco's Acti-Feed test on new fabrics.
- **Presser foot height:** set it to the material; on caps go down one click after touching, and use the top click for 3D puff. A foot set too low on thick goods causes needle deflection and breaks.
- **Hoop database and hoop choice:** an outdated hoop database causes "HOOP CHANGE FAILED", and one Melco OS build (v11.21.67) wrongly reports hoop limits on the WACF. Always select the hoop or cap frame actually fitted.
- **Design size limits:** older main PCBs take under about 130,000 stitches and 99 colour changes per design. Split bigger jobs.
- **Trim settings in the design:** very few stitches between trims or no tie-in/tie-off cause missed trims that look like a trimmer fault.
- **Speed:** Melco's thread break guidance assumes about 1,100 spm on flats and 900 spm on caps. Running at the 1,500 spm maximum on hard designs raises break rates.
- **File type:** send OFM or EXP where possible. A non-OFM or corrupt file can cause "Out of Memory".

## Official manuals, FAQs and support
- [Melco service site](https://www.melco-service.com/) — manuals and support pages for every Melco machine and software version, plus links to the Melco knowledge base
- [EMT16X support page](https://www.melco-service.com/emt16x.html) — Melco OS operator manuals (Advanced and Simplified), EMT16X technical and parts manuals
- [SUMMIT support page](https://www.melco-service.com/summit.html) — SUMMIT operator, technical and parts manuals
- [Melco embroidery machine comparison](https://melco.com/en-gb/comparison-of-embroidery-machines/) — SUMMIT, EMT16X and Bravo specs, speeds, fields and file formats
- [Amaya UK Melco help centre](https://help.amayauk.com/melco) — Melco UK distributor: manuals, maintenance videos and troubleshooting articles for EMT16X, EMT16 Plus and Amaya XT/XTS
- [Amaya UK: X / Y motor timeout or tracking error](https://help.amayauk.com/melco-x-/-y-motor-timeout/tracking-error-1) — reset steps for X/Y errors
- [Amaya UK: setting bobbin tension](https://help.amayauk.com/how-to-accurately-set-the-bobbin-tension) — gauge procedure and target range

## Frequently asked questions
### What file format does a Melco machine use?
Melco's own formats are OFM (DesignShop working file with wireframe and machine settings) and EXP (stitch file). Melco OS and the SUMMIT also load DST and ARTX. Send OFM or EXP when you can; a bad or non-OFM file is one cause of the "Out of Memory" message.

### Why does my Melco keep saying Z timeout?
A Z timeout means the needle drive could not finish its stroke. It is usually thread wrapped in the hook, wrong bobbin tension, stitches pulled too tight or a loose cap. Clear the hook, check the bobbin on a gauge, rehoop and oil the hook; call a technician if it still happens.

### What do the Melco keypad lights mean?
Slow red blinking is an upper thread break, fast red blinking is an empty or broken bobbin, and steady red means the E-stop is pressed (or the sequin device is on). Green on 2 s / off half a second is sleep mode; hold Start for 3 s to wake it.

### What should Melco bobbin tension be?
On EMT16, EMT16 Plus, EMT16X, Bravo, XT and XTS machines the target is 250–300 on the Melco bobbin tension gauge, pulled smoothly at about an inch per second. If the reading jumps around, replace the bobbin case.

### How often should I oil a Melco embroidery machine?
Oil the rotary hook at the start of each day and after every 4 hours of sewing, and follow the maintenance timers in Melco OS for the 2-, 10- and 30-million-stitch jobs. Use Melco oil and the correct greases; never use WD-40 as a lubricant.

### Why is my Melco stopping for thread breaks when the thread isn't broken?
Usually the thread is not around the thread break bar, the bobbin tension is off or the Acti-Feed lower limit is too high. Rethread, check the bobbin and reset thread break sensitivity to default before raising it one step at a time.

### Can I run several Melco machines from one computer?
EMT16X machines are modular: Melco says up to 30 heads can run from one PC over Ethernet. The SUMMIT uses its own touchscreen and shares designs through a network folder, and the Bravo is a single, non-modular machine.

## Diagrams

- [Five-minute diagnosis](https://easydigitizer.com/troubleshooter/img/diagnose-flow.svg): Where to start when the machine stops or sews badly.
- [Upper thread path](https://easydigitizer.com/troubleshooter/img/thread-path.svg): Every guide from the cone to the needle eye — the fix for most breaks and nests.
- [Why birdnests happen](https://easydigitizer.com/troubleshooter/img/birdnest.svg): What a nest is, the usual causes in order, and how to clear one safely.
- [The I-test for tension](https://easydigitizer.com/troubleshooter/img/tension-test.svg): Read the back of a satin column to balance top and bobbin tension.
- [Bobbin drop test](https://easydigitizer.com/troubleshooter/img/bobbin-drop-test.svg): Set bobbin tension before you touch the top tension.
- [Needle orientation](https://easydigitizer.com/troubleshooter/img/needle-orientation.svg): Long groove to the front, scarf to the hook, pushed fully up.
- [Hook timing](https://easydigitizer.com/troubleshooter/img/hook-timing.svg): What correct hook-to-needle timing and clearance look like.
- [Presser foot height](https://easydigitizer.com/troubleshooter/img/presser-foot-height.svg): Too high causes flagging and loops; too low drags and breaks thread.
- [Hooping layers](https://easydigitizer.com/troubleshooter/img/hooping.svg): Firm, flat and square — the root of most puckering and registration faults.
- [Caps: frame and sequence](https://easydigitizer.com/troubleshooter/img/cap-frame.svg): Cap frame set-up, centre-out sewing and safe sew height.
- [Cleaning and oiling points](https://easydigitizer.com/troubleshooter/img/maintenance-points.svg): Daily and weekly care points on a multi-needle head.

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Part of the EasyDigitizer embroidery machine troubleshooter: https://easydigitizer.com/troubleshooter/ · Agent playbook: https://easydigitizer.com/troubleshooter/agent.md · Not affiliated with any machine maker; the machine's own manual takes priority. Design-related sew-out problems (density, underlay, pull compensation): https://easydigitizer.com/help