BERNETTE B77 Common Problems and Troubleshooting

The BERNETTE B77 sewing machine is a versatile and affordable option for sewing and quilting enthusiasts. In this article, we will explore common problems that users might encounter while using the BERNETTE B77 and provide troubleshooting solutions to address these issues.

List of the BERNETTE B77 Common Problems

Here’s a list of 15 most common problems with the BERNETTE B77 sewing machine:

  1. Thread Breakage: Threads frequently breaking during sewing.
  2. Needle Jamming: Needles getting stuck or jammed while sewing.
  3. Uneven Stitches: Stitches not forming correctly or unevenly.
  4. Bobbin Winding Issues: Difficulty in winding the bobbin smoothly.
  5. Thread Tension Problems: Inconsistent tension causing loops or puckering.
  6. Machine Not Powering On: Difficulty in turning the machine on or lack of power.
  7. Feed Dog Problems: Feed dogs not moving fabric properly or unevenly.
  8. Stitch Selection Errors: Incorrect stitches being selected or not functioning.
  9. Loud or Unusual Noise: Unusual noises during operation indicating mechanical issues.
  10. Presser Foot Malfunction: Presser foot not lifting, lowering, or engaging properly.
  11. Automatic Thread Cutter Not Working: Failure of the automatic thread cutter to function correctly.
  12. Display Screen Issues: Problems with the display screen such as flickering or not displaying information accurately.
  13. Bobbin Case Problems: Issues with the bobbin case such as it getting stuck or not fitting properly.
  14. Software Glitches: Malfunctions or errors in the machine’s software affecting its operation.
  15. Needle Plate Damage: Damage to the needle plate causing sewing difficulties or fabric damage.

BERNETTE B77 Overview

Discover the BERNETTE B77 sewing machine, a versatile tool designed for sewing and quilting projects. With a focus on simplicity and creative potential, the B77 offers:

  • Easy navigation through a 5-inch color touchscreen
  • Quick operation using multi-function knobs
  • Included sewing consultant for valuable tips
  • Dual feed for fast and even fabric feed
  • Programmable foot control with back-kick function
  • Semi-automatic needle threader for convenience

Product Description

The BERNETTE B77 is an affordable sewing machine that opens up a world of creative possibilities. This computerized sewing machine is ideal for crafting your own clothes, quilts, and accessories. It’s designed to handle various materials, from delicate chiffon to sturdy leather, all while maintaining impressive stitch quality. The B77 includes:

  • 500 stitches, including 17 different buttonholes
  • 8 presser foot soles and a large extension table

With its dimensions of 14″D x 22″W x 17″H and a weight of 32 pounds, the BERNETTE B77 is a versatile and practical addition to any sewing workspace. It’s perfect for both beginners and experienced sewers.

Product Details

Item WeightProduct DimensionsItem model numberASINCustomer ReviewsBest Sellers RankManufacturerDate First Available
32 pounds14 x 22 x 17 inchesB77B086VVYMNK4.2 out of 5 stars (38 ratings)#215,746 in Arts, Crafts & Sewing
#51,744 in Sewing Products
BerninaApril 7, 2020

Causes of Common Problems with the BERNETTE B77

This section will delve into various common issues that users might encounter while using the BERNETTE B77 sewing machine. We will provide solutions and troubleshooting steps to help you address these problems effectively.

Common Problems with the BERNETTE B77 and Troubleshooting

1. Stitch Irregularities

Description: Stitches produced by the BERNETTE B77 sewing machine appear uneven or irregular, affecting the overall appearance of the fabric.

Cause: Uneven stitches can result from incorrect tension settings or improper threading of the machine.


  • Check the thread tension settings according to the material being sewn.
  • Ensure that the upper thread is threaded correctly through the machine’s threading path.
  • Inspect the bobbin area for any tangled thread or debris and clean it if necessary.

2. Needle Breakage

Description: Needles are frequently breaking while sewing with the BERNETTE B77.

Cause: Needle breakage can occur due to using the wrong needle type, improper needle insertion, or sewing through thick layers without the appropriate adjustments.


  • Ensure you are using the correct needle type and size for the fabric you are sewing.
  • Insert the needle with the flat side facing the back of the machine and secure it properly.
  • If sewing through thick layers, reduce the machine’s speed and use a walking foot or adjust the presser foot pressure.

3. Thread Bunching Underneath

Description: Threads are getting tangled and bunching up on the underside of the fabric being sewn.

Cause: Thread bunching can be caused by incorrect bobbin threading, improper tension settings, or a dirty bobbin case.


  • Check that the bobbin is wound and inserted correctly.
  • Ensure both the upper and bobbin thread tensions are appropriately set.
  • Clean the bobbin case area, removing lint or debris that may be affecting thread movement.

4. Skipped Stitches

Description: The BERNETTE B77 skips stitches while sewing, leaving gaps in the stitching lines.

Cause: Skipped stitches can occur if the needle is dull, improperly inserted, or if the machine is sewing too quickly.


  • Replace the needle with a new one, ensuring it’s the correct size and type.
  • Check that the needle is inserted correctly and tightened securely.
  • Reduce the sewing speed, especially when working with dense fabrics.

5. Uneven Fabric Feed

Description: The fabric is not feeding evenly through the BERNETTE B77, resulting in inconsistent stitching.

Cause: Uneven fabric feed can be caused by the pressure on the presser foot being too high or too low, or by using the wrong presser foot for the fabric.


  • Adjust the presser foot pressure according to the thickness of the fabric.
  • Ensure you are using the appropriate presser foot for the type of stitching and fabric you’re working with.
  • Clean the feed dogs and the presser foot area to prevent any obstructions.

6. Thread Keeps Breaking

Description: The thread on the BERNETTE B77 sewing machine keeps breaking during stitching.

Cause: Thread breakage can occur due to incorrect thread tension, using poor-quality thread, or a snag in the thread path.


  • Check and adjust the upper thread tension to match the fabric and thread type.
  • Use high-quality thread to reduce breakage and ensure smoother sewing.
  • Inspect the thread path for any rough edges or snags that might be causing breakage.

7. Uneven Buttonholes

Description: The buttonholes created by the BERNETTE B77 are uneven in size or shape.

Cause: Uneven buttonholes can be caused by incorrect buttonhole settings, improper positioning of the fabric, or a malfunctioning buttonhole foot.


  • Refer to the user manual to ensure you are using the correct buttonhole settings.
  • Position the fabric correctly and secure it in place before starting the buttonhole.
  • Check the buttonhole foot for any obstructions or issues and replace if necessary.

8. Noisy Operation

Description: The BERNETTE B77 sewing machine is making unusual noises during operation.

Cause: Noisy operation can be caused by a loose part, debris in the machine, or a need for lubrication.


  • Inspect the machine for any loose screws, parts, or accessories, and tighten them as needed.
  • Clean the machine of any lint, dust, or debris that might be causing the noise.
  • If appropriate, apply a drop of sewing machine oil to the designated areas according to the user manual.

9. Thread Jam in Bobbin Area

Description: Threads are jamming in the bobbin area of the BERNETTE B77, causing disruptions in sewing.

Cause: Thread jams can occur due to incorrect bobbin insertion, improper threading, or a malfunctioning bobbin case.


  • Ensure the bobbin is inserted in the correct orientation and is wound evenly.
  • Double-check the threading path for both the upper thread and the bobbin thread.
  • Inspect the bobbin case for any damage or issues that might be causing the thread jam.

10. Unresponsive Touchscreen

Description: The touchscreen of the BERNETTE B77 is unresponsive or not registering touch commands.

Cause: Unresponsive touchscreen issues can be due to calibration problems, dirt or smudges on the screen, or software glitches.


  • Calibrate the touchscreen according to the user manual to ensure accurate touch registration.
  • Clean the screen with a soft, lint-free cloth to remove any dirt, smudges, or residue.
  • If the issue persists, perform a soft reset or check for any available software updates.

11. Uneven Tension Across Layers

Description: When sewing through multiple layers of fabric, the BERNETTE B77 produces uneven tension and stitching.

Cause: Uneven tension across layers can be caused by inconsistent fabric thickness, incorrect presser foot pressure, or inadequate needle choice.


  • Use a walking foot or dual feed mechanism when sewing multiple layers to ensure even fabric feeding.
  • Adjust the presser foot pressure to accommodate the fabric thickness and prevent uneven tension.
  • Select the appropriate needle type and size for the fabrics to avoid tension issues.

12. Bobbin Thread Not Catching

Description: The BERNETTE B77 fails to catch the bobbin thread properly, resulting in loose stitches.

Cause: Bobbin thread not catching can happen due to incorrect bobbin insertion, improper threading, or a damaged needle.


  • Ensure the bobbin is inserted correctly and is wound evenly without any tangles.
  • Double-check the bobbin threading path, making sure the thread is securely in place.
  • Inspect the needle for damage or dullness and replace if necessary.

13. Thread Keeps Tangling

Description: The thread on the BERNETTE B77 keeps tangling and creating knots during sewing.

Cause: Thread tangling can be caused by incorrect threading, using low-quality thread, or a buildup of lint in the machine’s thread path.


  • Re-thread the machine carefully, ensuring the upper thread follows the correct path.
  • Opt for high-quality thread to reduce tangling and knot formation.
  • Regularly clean the machine’s thread path and bobbin area to prevent lint buildup.

14. Fabric Puckering

Description: The fabric sewn with the BERNETTE B77 appears puckered or gathered, affecting the overall finish.

Cause: Fabric puckering can be caused by incorrect tension settings, using the wrong presser foot, or sewing too quickly.


  • Adjust the thread tension according to the fabric type and stitch being used.
  • Use the appropriate presser foot for the fabric and stitch to prevent excessive gathering.
  • Reduce the sewing speed, allowing the machine to feed the fabric more evenly.

15. Motor Overheating

Description: The motor of the BERNETTE B77 becomes excessively hot during prolonged sewing sessions.

Cause: Motor overheating can occur due to extended use without breaks, using the machine at high speeds, or a malfunctioning motor.


  • Take regular breaks during extended sewing sessions to allow the motor to cool down.
  • Adjust the sewing speed to a moderate level, especially when working on demanding tasks.
  • If the motor continues to overheat, contact the manufacturer for a professional assessment.

16. Stuck or Jammed Feed Dogs

Description: The feed dogs on the BERNETTE B77 are stuck or jammed, preventing smooth fabric movement.

Cause: Stuck feed dogs can result from thread tangles, debris accumulation, or a mechanical issue.


  • Remove the fabric and inspect the feed dogs for any tangled threads or foreign objects.
  • Clean the feed dogs area thoroughly to ensure smooth movement.
  • If the issue persists, consult the user manual or seek professional repair.

17. Skipped or Misaligned Stitches

Description: The BERNETTE B77 produces skipped stitches or misaligned stitching lines.

Cause: Skipped or misaligned stitches can result from incorrect needle threading, needle damage, or a timing issue.


  • Re-thread the upper thread, ensuring it follows the correct path through the machine.
  • Inspect the needle for damage or bending, and replace it if needed.
  • If the problem persists, the machine’s timing may need adjustment; consult a professional technician.

18. Inconsistent Bobbin Tension

Description: The tension of the bobbin thread on the BERNETTE B77 varies, leading to uneven stitching.

Cause: Inconsistent bobbin tension can be caused by improper bobbin threading, worn-out bobbin case, or a dirty bobbin area.


  • Ensure the bobbin is threaded correctly and inserted into the bobbin case evenly.
  • If the bobbin case shows signs of wear, consider replacing it to maintain proper tension.
  • Clean the bobbin area regularly to prevent lint buildup that could affect tension.

19. Broken Needle Threader

Description: The automatic needle threader on the BERNETTE B77 is not functioning or breaks frequently.

Cause: A broken needle threader can result from misalignment, damage, or wear over time.


  • Inspect the needle threader for any visible damage or misalignment and attempt to realign it gently.
  • If the threader is excessively worn or damaged, consider replacing it if possible.
  • Manually thread the needle if the automatic threader remains non-functional.

20. Limited Stitch Options

Description: The BERNETTE B77’s stitch options seem limited, and certain stitches are not available.

Cause: Limited stitch options can be due to incorrect machine settings, a software glitch, or a malfunction.


  • Review the machine’s settings and ensure you are in the correct mode to access all available stitches.
  • If the issue persists, try resetting the machine to its default settings.
  • If specific stitches are consistently unavailable, there might be a malfunction requiring professional inspection.

21. Uneven Feed Dogs Movement

Description: The feed dogs on the BERNETTE B77 are moving unevenly, resulting in irregular stitching.

Cause: Uneven feed dog movement can be caused by dirt, debris, or a mechanical issue in the feed dog mechanism.


  • Clean the feed dog area thoroughly to remove any dirt, lint, or obstructions.
  • Check the feed dog mechanism for any visible issues or signs of misalignment.
  • If the problem persists, consider seeking professional repair.

22. Fabric Slippage

Description: The fabric slips or shifts while sewing on the BERNETTE B77, leading to uneven seams.

Cause: Fabric slippage can result from incorrect presser foot pressure, using the wrong presser foot, or sewing too quickly.


  • Adjust the presser foot pressure to grip the fabric properly without causing distortion.
  • Use a presser foot appropriate for the fabric type and stitch being used.
  • Control the sewing speed, ensuring the fabric feeds smoothly without slipping.

23. Bobbin Winding Issues

Description: The BERNETTE B77 experiences difficulties while winding the bobbin, resulting in unevenly wound bobbins.

Cause: Bobbin winding issues can be caused by improper threading of the bobbin winding mechanism, tangles, or a malfunctioning bobbin winder.


  • Ensure the bobbin winding mechanism is threaded correctly and engaged properly.
  • Check for tangles or knots in the thread as it winds onto the bobbin.
  • If the bobbin winding problem persists, consult the user manual or seek professional assistance.

24. Thread Fraying

Description: The thread used with the BERNETTE B77 starts to fray, leading to stitching problems and weak seams.

Cause: Thread fraying can occur due to poor-quality thread, using a needle with a small eye, or excessive tension.


  • Opt for high-quality thread that is less prone to fraying during sewing.
  • Choose a needle with an appropriate eye size for the thread type.
  • Adjust the thread tension to a balanced setting that prevents excessive pulling and fraying.

25. Fabric Not Feeding

Description: The fabric doesn’t feed through the BERNETTE B77 despite using appropriate settings, causing stitching issues.

Cause: Fabric not feeding can be due to a disengaged feed dog mechanism, incorrect presser foot pressure, or tangled fabric.


  • Ensure the feed dogs are engaged and raised to allow proper fabric movement.
  • Adjust the presser foot pressure to grip the fabric without hindering its movement.
  • Check for fabric tangles or obstructions that might be preventing smooth feeding.

BERNETTE B77 Sewing Machine User Reviews

Positive Reviews from BERNETTE B77 Sewing Machine Users

  • Many users were satisfied with the overall stitch quality and precision, achieving professional-level results.
  • Some users appreciated the ease of use, especially the intuitive touchscreen interface and the convenience of multi-function knobs.
  • Several users were impressed with the variety of stitches and buttonholes available, allowing for creative exploration.
  • Users found the dual feed feature particularly helpful for sewing multiple layers and working with various fabrics.
  • Many customers highlighted the machine’s durability and quiet operation, noting that it felt like a high-quality investment.

Overall, the positive feedback suggests that the BERNETTE B77 sewing machine delivers on its promise of offering creative possibilities, excellent stitch quality, and user-friendly features.

Negative User Reviews of the BERNETTE B77 Sewing Machine

  • Some users expressed dissatisfaction with the machine’s reliability, reporting issues like motor overheating and jamming.
  • Several users faced difficulties with the automatic needle threader, citing frequent malfunctions or breakages.
  • A number of customers encountered problems with tension inconsistency, resulting in uneven stitches and frustration.
  • Certain users mentioned difficulties in navigating through the machine’s functions and settings, finding them less intuitive.
  • Some users were disappointed with customer support experiences, stating that their concerns were not adequately addressed.

While the majority of users had positive experiences, it’s important to note that there were instances of negative feedback regarding issues such as machine reliability, threading complications, and customer support interactions.

Based on the aggregated user reviews, the BERNETTE B77 sewing machine received widespread praise for its stitch quality, ease of use, and creative features. However, some users did encounter issues related to reliability, threading, and customer support. Despite these challenges, the overall sentiment leans towards satisfaction, with the majority of users expressing positive feedback.

BERNETTE B77 Sewing Machine Manual

The operating instructions for the BERNETTE B77 sewing machine can be found on the manufacturer’s website. It’s recommended to refer to the manual for comprehensive guidance on setting up and using your sewing machine effectively.

Frequently Asked Questions about BERNETTE B77 Sewing Machine

  • Q: Why is my thread breaking frequently?

A: Frequent thread breakage can result from incorrect thread tension, using poor-quality thread, or a snag in the thread path. Check and adjust the tension, use high-quality thread, and ensure a smooth thread path.

  • Q: Why are my stitches uneven or puckered?

A: Uneven stitches and fabric puckering can be caused by incorrect tension settings, using the wrong presser foot, or sewing too quickly. Adjust tension, use the appropriate presser foot, and control sewing speed for smoother stitches.

  • Q: What should I do if the bobbin thread isn’t catching?

A: If the bobbin thread isn’t catching, ensure correct bobbin insertion, proper threading, and examine the needle for damage. Correct any issues and ensure proper needle threading.

  • Q: Why is my machine making unusual noises?

A: Unusual noises can be due to loose parts, debris, or the need for lubrication. Tighten loose parts, clean the machine, and lubricate as instructed in the manual.

  • Q: How can I prevent fabric slippage during sewing?

A: Fabric slipping can be prevented by adjusting presser foot pressure, using the appropriate presser foot, and controlling sewing speed. These steps ensure proper fabric grip and movement.


Whenever you encounter a problem with your BERNETTE B77 sewing machine, it’s recommended to consult the manual provided by the manufacturer.

Additionally, if you face challenges that aren’t resolved by the troubleshooting tips, you can reach out to the customer service or service center for expert assistance. This ensures that any issues are addressed effectively and you can continue enjoying your sewing experience with the BERNETTE B77.

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