I had a similar problem over 30 years ago. Turned out to be the needles. That machine did not like the brand of needle I had bought. The shaft of the needle was a little bit thicker than the machine brand ones. Maybe a tenth of a millimetre, who knows. As a result it didn't 'fit' into the needle shaft properly.
Result: lots of missed stitches, broken needles and finally scarring on my bobbin case when I took the bobbin out to do a test run to find out the problem once and for all time.
Anyway, my suggestion is buy the brand of needle that the machine is and see if that fixes the problem.
Since then, I only use the machine brand needles or Schmitz needles in any of my machines and that part, at least, works like a dream.
Good luck
Thank you all for your insight. This is a new to me machine. It has been very frustrating as I bought it to embroider and there is not a chance that is going to happen. I have methodically checked the machine threading, replaced the needle and made sure it is properly inserted and the right size for the project, watched it go up and down while hand turning to make sure it isn't hitting anything. Cleaned out the bobbin casing, properly inserted the bobbin, pulled the thread through the feed plate. My conclusion is it's probably a timing issue. I am going to take it to a dealer and ask for a "tune up and alignment". The seller gave me my money back and said keep the machine. So, I am out only the cost to fix it, if it can be fixed. That will answer the embroidery issues as well. When I check to make sure the embroidery arm was making proper contact, I noticed the receiving side that is mounted in the machine is loose. Maybe that's why it errors: Disk Not Accepted.
This sounds as if the seller knew there was something wrong. Since you got your money back it will probably be worth to have the machine checked out and repaired. I hope to see something you embroidered in the future. My dealer often takes in machines working or not as trade ins for a new one. That is another possibility. For now lets hope she can be made right and stitching away in the future.
Is the machine a NEW one or just new to you. If it is second hand it could be it needs a service. Could be a tiny bit of a needle caught in the bobbin area.
So far no one has suggested that perhaps your thread is not coming off the spool so it gets really tight and pulls backwards. I had a D1 and ne ver had any problems. Hope you get this solved as it is frustrating to get a new machine and not have it hum right along.
Just a thought.....
I would check that your needle is actually in the centre of the plate and not slightly off centre, which would, when you set it to zig zag, possibly cause it to hit the needle plate when it moves from side to side.
I had this happen to me not long ago after I had moved the needle a little towards one side when sewing in a zipper and I had forgotten to re-centre it.
This is just for info, I have a Topaz 30 and it runs like a top. Had it cleaned and was making an ITH purse. It sewed the whole thing wonderfully until the last "stitch around". Then I broke 3 needles. I put safety glasses on, slowed the speed of the machine to a crawl and turned my head sideways to see what was happening. The needle was too close to the edge of the needle plate hole. When a tiny bit of tension was put on the thread and needle it pulled it ever so slightly over the plate and SNAP ! It turned out to be a very simple adjustment of the needle bar, but it wasn't simple for me because my "tuner up person', lives in another state. Any regular sewing machine service person should be able to check this really quickly.
I would say that your machine is slightly out of time, and that after several stitches the needle catches up with the shuttle and hits it.
Hmmm, I agree with Rescuer...do some trials with same fabric and switch out the thread spools...also, does it embroider okay or are you breaking needles when embroidering too? Five packages of needles is a lot! Had it been recently services before you got it? If you got it from a dealer, I would go back and have them check it out...
In the sewing mode I have no clue. Why would the needle bend. I hope someone will come along with some ideas.
If the stitch looks right, then I would say you might have a burr on the bobbin race that your needle is bumping or a timing issue. It may be as simple as your thread. That is where I would start. If you can use the same fabric with different thread -- then toss the bad spool.
Timing issues are a dealer/repair trip.