i have been working on a quilt for a monthw/no problems until 2 days ago.suddenly i'm getting "tangled upper thread ,bent needle"warnings. can't tell you how many times i've re-threaded,changed thread & needles to no avail.i'm tearing my hair out !!! justgot it back from the shop after 4 wks!it was great til now . any help would be appreciated SO much.don't want to have to give it up AGAIN.thanx for any help you can give me

I'm not sure but several things can be happening,you might have extra thread in your machine from when you threaded it and it tangled or broke. Also always cut your thread by the spool and pull out of the needle so you don't get fur balls that can cause this problem. Last could just be plain old tension. It should be still under warrenty from the repair shop too.

You really need to contact the repair place and give them a chance to look at the machine again. I know how hard it is to be without the machine, but I think that is your only option.

Have you :

rethreaded the machine
rewound the bobbin
put in a new needle
cleaned the bobbin area
try a new thread on the top of the machine

We are doing some trouble shooting on an sq9000 in another post. http://www.quiltingboard.com/t-47785-1.htm
BJayne notes she has cs6000 and it seems she is having the same problem as you are. She notes her solution but I don't have a visual of what she is describing. I was going to ask for more detail in case it would be helpful on the sq9000 as well.
I have the sq9000 and ex660. I was breaking needles bad. I have always zipped through a straight seam using a fast speed, lifting the presser foot, pulling the threads long enough to snip them. I have learned when I do this on these two machines I am pulling the thread out of the bobbin thread path. When I start my next stitches the bobbin thread tangles in a knot with the top thread. The bobbin can not spin so the bobbin thread pulls against the top thread bending and/or breaking the needle.
You are welcome to read the other post too in case there is something that might give you some ideas.
If you recognize your solution when you get the machine working again please will you let us know.
Regards, Dorothy

Sorry this updated twice.

thanx so much for your fast replies !!just came fromdr's so haven't had a chance to try your suggestions but am going to do this todayfor sure !i think the bobbin may be goofing up. the machine has an auto cutter, but noticed when warning comes up that the bobbin thread hasn't cut. too dumb to realize that might be the problem!! will let you all know what happens. thnx SO much again,,,dar

well itried everything posted & nothing has worked ,so back to the shop again,tomorrow i hope.will keep you posted

Are you using a walking foot?

DOROTHY brings up a good point - LET the Machine Do The Work - let it cycle through the cut thread cycle - patience ladies!

my girlfriend tried it yesterday, noticed that when i use tbuilt -in dec or utility st. is when it acts up.like it forgets what it's supposed to do,,starts making strange noise then warning message comes on & machine stops. I AM SO FRUSTRATED ! esp.since when i take it back to shop it will be sent out again...........sorry abought the bi........just need to vent thaanx for listening , dAR

did you get your machine fixed???