Weird Sewing Machine Problem
 

Well, phooey. My beloved sewing machine (Brother PC420PRW) suddenly started acting weird a couple of hours ago. It sews just fine ... no problems at all ... but when you push the button to automatically cut the threads, the thread cutter makes a rather unhappy grinding sound. :shock: Neither threads are cut.

Here's what I've done:

Changed the needle
Re-threaded both upper and lower threads (several times)
Changed the spool of thread to a different one
Changed the bobbin to a different one
Turned the machine off and back on (several times)
Spent over an hour cleaning it. I already keep it as clean as I possibly can, but I did find some overlooked lint mooshed up under the feed dog mechanism. Cleaned that out.
Googled my fingers off trying to find a solution.

Nothing helped. :( I really miss the thread cutter. It saves so much time AND thread.

But that's not the only thing ...

While I was cleaning the lint out, I noticed something odd about the bobbin case. It looks like it's been broken or "chewed" off ... perhaps somehow jabbed by the needle. (??) See pic below. I did break a needle about a month ago while sewing a multi-layered project. I didn't think anything of it, and if the bobbin case was damaged as a result, I didn't notice it (and I sew pretty much every day!). There were no further problems at all until today when the thread cutter suddenly stopped working. Weird. I don't know if the broken bobbin case could be affecting the thread cutter, and if it is, how did it take a month (??) to cause a problem?

I've looked and looked, but I can't find the hickey-do that actually cuts the threads. The manual is no help whatsoever. It does say not to press the thread cutter button without fabric and thread present, so I can't just press the button with the bobbin area opened up and watch to see what gadget actually tries to cut the thread. If I could SEE it, I could probably find the culprit! LOL! ;)

I'll get a new bobbin case ordered ASAP, but in the meantime, do you think the thread cutter problem could be caused by something else? Do you know of anything else I could check? Thanks in advance for any advice/thoughts you might have! :) (Whew, this was a long message!)

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I love my thread cutter. I have no suggestions as I would of done everything you've done.

Your bobbin case...oh no! Looks like a gremlin was hungry!

take it in for repair.
if you wait too long, you will end up with bigger and more expensive problems.

the PC420PRW is definitely worth fixing before replacing.

After trying to cut "blue jeans" thread, my Babylock Esante thread cutter did not work properly. Had to have it replaced. So now I scissor cut any heavy thread.

I have had to have my cutter replaced periodically. Think about your rotary blade, it gets dull. It sounds like yours has also been bent. Time for a spa visit, it's a job for the pros.
You can't see the cutter because unless it's in use, it's tucked up under the housing of the machine bed.

I agree with PaperPrincess. It's time for a new thread cutter and yes prolific stitchers can wear them out. As for your bobbin case, I did a similar thing to mine. It happens. We use our machines a lot and machinery does need maintenance for best performance. Give your poor machine some TLC.

I won't buy a new machine unless it has an auto thread cutter. I saves a lot of thread and no thread tails to clean up after piecing.

Update: I got my mechanically-inclined DH to look at it when he got home from work a little bit ago. There's a little hook that comes out, grabs the threads, and somehow pulls them to the cutter (which we can't actually see). The hook keeps getting stuck in the "out" position. It did that once before, a long time ago. Turning the machine off, then back on, makes the hook retract. However, the next time I push the cutter button, the hook stays "out" again.

It could just be a coincidence, but the hook reaches directly toward the broken area in the bobbin case, so it's possible that the problem lies there. I ordered a new bobbin case a little bit ago. Should be here next week.

It's now cutting the top thread, and isn't making as unhappy of a sound as it previously was. It still doesn't sound quite right, though, and the bobbin thread isn't being cut. The bobbin thread is staying in the hook when it's in the "out" position.

The machine is just expensive enough (paid $399) to not be considered "disposable", but not so expensive that I can justify a big repair bill. Kind of frustrating! I'm sure it's out of warranty since I've had it almost 3 years now. The only local authorized Brother service center is a business I don't care to deal with (they were horribly rude to DH). The next-closest is 70+ miles away. I'm not sure if there are any local "un-authorized" repair shops that'll work on it.

With a little luck, the new bobbin case may fix it. >>crosses fingers<< I'll try that first, then go from there if it doesn't work.

Thanks so much for the responses, and if anyone else has any ideas, let me know! :)

I have a Babylock Decorator's Choice. Most of the time it works well but when it doesn't, it is annoying. I just had my machine to the repair shop about a month ago. They did fix something with the thread cutter but mine is now making that funny sound when the cutter is engaged and the bobbin thread is not cut. Before that, I had to pull on the top thread when I started to sew so the thread would stay in the needle eye. My solution for now is to cut the thread manually, does use more thread but saves on aggravation. My repair at the time was $100. I would never pay an amount as a diagnostic fee. Try and find a repair shop nearer to your home. They may not sell machines but do repair a lot of brands. My daughter who lives in Michigan found a repair shop close to home and they did a great job for her. She likens getting the machine repaired to having an oil change in the car. On another note, I'm not sure Jazz has a thread cutter. Does anyone know about this?