Sewing machine help?

[goldenblackbird.livejournal.com]

I'm not sure where to post this, and I'm desperate =(

I sew a lot. Right now I'm trying to perfect a design and method to making small fabric dog collars and harnesses. I was in the middle of sewing a martingale loop for my own female dog's collar, when the thread started to get very loopy on the bottom. I adjusted the tension up and it got worse, down and... It got worse. I rethreaded it. I adjusted. I yelled at it. Finally I took a flashlight to it and started to pull the thread right through the tension plates, no restriction.

At the time, the plates were set to their highest/tightest setting. I saw a HUGE gap between the plates that wasn't closing, that clearly couldn't hold a thread. A piece of felt would've fit through effortlessly.

It's a Brother XL 2600, and it's making me so mad, I'm thinking I should've just invested in an overlock machine when I could instead of saving some money on another machine upgrade: this is number three. Has anyone had this problem, or similar, on this machine- or similar!- and been able to fix it themselves? I'm so broke right now I couldn't get it repaired at my fantastic local fabric shop if I begged =(

If not, the damn thing is probably going to find a nice home in a trash can, and I'll just put my projects on hold until I can get a nice overlock.