This guide helps you troubleshoot Sun Joe® grass string trimmers and cordless grass shear + hedger units. Use the dropdown sections to check battery-powered string trimmers, electric string trimmers, cordless grass shear + hedger models, spool line issues, line cutter issues, and blade care tips.
Sun Joe® Troubleshooting
Grass String Trimmer & Grass Shear + Hedger Troubleshooting
Use this guide to troubleshoot common power, cutting, spool, line cutter, blade, and charging issues.
Safety First Always turn the unit OFF and place it on a stable surface before troubleshooting. For electric models, unplug the unit and disconnect the extension cord. For battery-powered models, remove the battery if applicable. Keep hands, fingers, and loose clothing away from the spool, line cutter, blade, and cutting area.
Before You Start Confirm whether you have a battery-powered string trimmer, an electric string trimmer, or a cordless grass shear + hedger. Use the matching section below so the correct power, spool, and blade checks are followed.
Battery String Trimmer Check battery charge, battery seating, spool debris, and line length.
Battery Powered
Battery Powered
Electric String Trimmer Check outlet, outdoor extension cord, spool debris, and line cutter.
Corded Electric
Corded Electric
Grass Shear + Hedger Check charge, charger connection, start sequence, and blade attachment.
Cordless
Cordless
📌 Quick Reference
Use this table to choose the correct troubleshooting section before starting.
| Product Type | Common Issue | Start Here |
|---|---|---|
| Battery-powered string trimmer | Motor will not run, runs slowly, or line does not cut off | Battery charge, battery seating, spool cleanup, and line cutter check |
| Electric string trimmer | Motor will not run, runs slowly, or line does not cut off | Power outlet, outdoor extension cord, spool cleanup, and line cutter check |
| Cordless grass shear + hedger | No power, will not start, or blade attachment issue | Charge, charger removal, trigger sequence, and blade attachment check |
| Blade or cutting performance | Grass shear or hedger blade is dirty, dry, or cutting poorly | Blade Care Tip |
🔋 Battery-Powered String Trimmer Models
Use these steps if the string trimmer motor will not run, runs slowly, or the line is not cutting off correctly.
- Make sure the battery is fully charged.
- Make sure the battery is fully seated and clicks securely into place.
- Turn the trimmer OFF and remove the battery before checking the spool area
- Remove the spool and clean out any grass, weeds, or debris.
- Trim the spool line so it just reaches the line trimming blade.
- Check whether the line cutter in the guard is covered, damaged, or missing.
- Rewind or trim the line back to the line cutter.
- Reinstall the spool securely, then reinstall the battery and test again.
Important Remove the battery before checking or cleaning the spool, guard, line cutter, or cutting area. Do not use the trimmer if the guard or line cutter is damaged or missing.
⚡ Electric String Trimmer Models
Use these steps if the electric string trimmer motor will not run, runs slowly, or the line is not cutting off correctly.
- Make sure the trimmer is connected to a working power outlet.
- Make sure the extension cord is securely connected and rated for outdoor use.
- Refer to the extension cord chart in the product manual to verify the correct cord gauge and length.
- Turn the trimmer OFF and unplug it before checking the spool area.
- Remove the spool and clean out any grass, weeds, or debris.
- Trim the spool line so it just reaches the line trimming blade.
- Check whether the line cutter in the guard is covered, damaged, or missing.
- Rewind or trim the line back to the line cutter.
- Reinstall the spool securely, reconnect power, and test again.
Important Do not use a damaged, frayed, worn, or incorrect extension cord. Always unplug the trimmer before checking or cleaning the spool, guard, line cutter, or cutting area.
✂️ Cordless Grass Shear + Hedger Models
Use these steps for cordless grass shear + hedger models, including HJ604C and HJ605CC-style units.
- Make sure the unit is fully charged.
- Make sure the unit is not connected to the charger before use.
- Place your thumb on the top handle, push forward, then pull the trigger.
- If the unit has no power, test the second blade attachment if available.
- Make sure the blade attachment is seated correctly before testing again.
Important Do not use the grass shear + hedger while it is connected to the charger. Keep hands and fingers away from the blade area before, during, and after use.
🧵 Spool Line or Line Cutter Issue
Use this section if the trimmer turns on but the line is not feeding, cutting correctly, or reaching the line trimming blade.
- Turn the trimmer OFF and disconnect power.
- For battery-powered models, remove the battery. For electric models, unplug the extension cord.
- Remove the spool.
- Clear grass, weeds, or debris from the spool area.
- Trim the spool line so it just reaches the line trimming blade.
- Check whether the line cutter in the guard is covered, damaged, or missing.
- Rewind or trim the line back to the line cutter.
- Reinstall the spool and test again.
Important Do not operate the trimmer if the guard or line cutter is damaged or missing. The line should only extend to the line trimming blade.
🧹 Blade Care Tip
Keeping the blade clean and lightly oiled can help support smoother operation and better cutting performance.
- Turn the unit OFF before cleaning.
- Make sure the blade area is safe to handle.
- Remove grass clippings or debris from the blade area after use.
- Lightly oil the blade as needed to support smoother operation.
- Store the tool in a clean, dry area.
Important Do not inspect, clean, oil, or adjust the blade area while the tool is running.