I have a Janome 6500. While sewing it suddenly stopped and the BM init error came up. Everything was locked up. What could be wrong?

Question edited for clarity.
Please don't type in all CAPS, it is considered SHOUTING and is harder to read.

Sewing machine tension is a delicate tug of war between the bottom Bobbin tension and the Upper tension to put the loop between the 2 layers of fabric. You set the Bobbin tension first and the the top tension depends on the fabric and the thread used.

Your Bobbin tension is very very loose to be not tensioning at all or the top tension is too loose.

Adjusting The Tension - Janome Memory Craft 6500 ...

ManualsLib https://www.manualslib.com > ... > Instruction book

Janome Memory Craft 6500 Professional Manual Online: balancing thread tension, Adjusting The Tension. Correct Tension: The Ideal Straight Stitch Has Threads ...

Best video on tension

The TD init error indicates an initialization problem with the automatic thread tension motor. Either a wire connection between this motor and the control board is loose or damaged or the motor has failed. This is from the Janome Service document: http://www.janomeservicevideos.com/wordpress/wp-content/uploads/2015/02/Error-Codes.pdf .

Since the MC6500 is a computer with a sewing machine, you may not want to repair this yourself. A sewing machine service technician is a better choice to look at the machine, if you do not have training with electrical repairs. I don't know if a Janome repair technician will have the thread tension motor for this sewing machine. However, none of the other sites for sewing machine parts that I checked have this part in stock.

I wish that I had better news for you.

Cindy Wells

not sure if this link will help you out but go to this link and scroll down the page and see if it helps.
bobbin will not wind Janome 6500 Google Search

Fuse blown
Janome New Home Sewing Machine MC 9000 Workshop Service Repair Janome...

it's possible that there is a computer problem and a timing problem on the machine

That's an initiation error. I would call Janome direct and ask them.

bm init

Hi, If you can get the top cover off, spray the whole shaft and moving parts with wd-40, let it sit for a few hours and then try it again. If it still does not move, spray it again and let it sit over night.
It should work. If not, you'll have to take to your local repair shop. But try the WD-40 first.

the lock button is stuck on the front n of you mech.