Uggh! My early warning signal didn't work!!
 

Okay, so I'm supposed to get a warning when my bobbin is almost empty. Sewed one whole side of binding, got ready to turn and hello....out of bobbin thread! I checked and the ringer is on and set to loud so I can hear it above my sewing. Do I take it in for something like this? It seems so minor, but apparently I really need it!

I wish I had a warning bell. LOL

Was the bobbin different in any way? Like old or hazy? I'd wait until it did it again with a different bobbin, just in case it was just having trouble with that particular one.

dust out the bobbin case might help

My machine has an early warning as well - and when it stopped working I found a bit of of lint that was missed in the area of the sensor. I just followed the bobbin thread and made sure the entire pathway was clear of lint and it started working again.

My Bernina 1530 has no warning bell but if I listen carefully, my Bernina makes a slightly different noise. I learned that from my dealer.

Were you using purchased pre-wound bobbins? Some of these won't trigger the alarm.....

I took mine in once and that was one of my minor issues - he told me it was probably dirty. He cleaned it and it worked great...now it's dirty again. I need to be get my vacuum cleaner out and try that...but I'm lazy.

My machine tells me what percentage of thread I have left when it gets down to 20% so I can plan ahead -- so I don't have to change thread at an inappropriate place. We are so spoiled!

Mine has no warning either, but I can hear a slight difference in sound--if I'm paying enough attention! :)

Yep, 'tis true. :)
I can hear it nearly every time within half an inch if stitching.

This was going to be my suggestion as well. My brother also has a warning notice that pops up on the screen when my bobbin is low. Of course it usually pops up when my bobbin is still half full, so I have to constantly be checking so the same doesn't happen to me. When the fuzz and lint really starts building up inside my bobbin case area, my bobbin indicator stops working all together and I know it's time to get my machine serviced.

I now know to brush out my bobbin case area with every bobbin change so that it doesn't build up so badly.

Take it in - I had the same problem one time and I am so used to that signal that I just can't sew without it. I have a preventive maintenance policy so I take my machine in quarterly just for them to give it a really good cleaning but I can take it in whenever I have any problem, no matter how minor.

Use a bobbin for the top thread, so they will run out together and you will notice it! (A hint from my quilt guild)

It also won't work if the bobbin case door is open. Ask me how I know.

I find a can of pressured air really works well to clean out all those un-reachable areas. Get it at the office supply store.

When I use a very fine thread, my bobbin low warning seems not to work. Try a bobbin with different thread.

Since I only sew on a vintage machine, there is no warning and I don't really need one. I always notice immediately when the bobbin thread has run out.

Also, I read that using pressurized air and even blowing is not recommended as you can blow loose lint further into you machine causing more problems.

I have a Babylock and if I wind the bobbins myself the bobbin warning works pretty good, however I use a lot of prewound bobbins and they apparently have a lot more thread on them so it warns, and warns, and warns for the last fourth of the bobbin. It is not all it's cracked up to be!

My dealer told me the same thing. He said it's fine to use on the outside of the machine to blast of general dust and thread lint, but for the inside it's a no-no. I use a skinny paintbrush with splayed-out bristles and a chenille stem to snag dust from deep inside the machine and it's amazing how much stuff I can find within reach to pull out of there...who knows how much stuff is out of reach!!

I can also hear a difference when the bobbin is out

I have found that my warning for low bobbin thread does not work when my bobbin area needs a good cleaning. Try taking the bobbin area apart and giving it a good cleaning before taking it in for servicing. Hope that does it for you.

I'd say clean the bobbin area and give it a try. I have used canned air since a teacher at my dealer showed how to use it by first removing the throat plate and holding the can behind the machine. That way the air blows out the front. I do also have a small vacuum cleaner that I used between projects. Usually, though, just cleaning with the tiny brush between bobbin fill-ups works find. Of course, I don't have a warning signal, so I can really address your problem.
Wishing you good luck solving the problem!

I actually noticed this problem right AFTER I cleaned out the machine. I've been changing bobbin colors for different projects recently so a bobbin hasn't had the opportunity to get empty. Maybe I pushed a piece of lint someplace that it shouldn't be. I'll go back and clean it again. Thanks everyone!!!

On my machine, the sensor which triggers the ringer doesn't work if the bobbin area is clogged up with dust and lint.
Try cleaning your bobbin area and this might make a difference.

My machine seems to do that every now and then, Sometimes cleaning the bobbin case thoroughly helps as others have said. I'm not sure I would take my machine in just for this unless it was due for a tuneup. I only have one machine and I am lost without it.

Sometimes there is a little bit of lint in the bobbin area that blocks the bobbin sensor. It can be just a tiny speck. Clean the bobbin area with a lint brush and see if that helps.

I don't have a warning bell but I can hear a distinct difference in the machine when the bobbin empties

When my bobbin bell doesn't go off it means I need to clean out my bobbin area.

This happened to me even though I cleaned the area out and tried different bobbins. I just learned to live with it. A few months later when I had the machine in for its annual tune-up I mentioned it to the technician. He checked it out and found that the little light bulb that sends a beam of light through the plastic bobbin was burned out. He replaced the part, it worked and I was a happy camper.

Cleaning it out after each project should prevent these types of things. Dust and lint build up and keep it from sensing the low thread properly. I love that feature!