I have a singer simple sewing machine 3210 and I tried to use it for the first time today. I threaded everything fine and started to sew and after 15-20 seconds it popped and sort of exploded. The stitching looks fine. I think this was the lightbulb? There are shattered bits of thin glass (may have been white but is black now). Is this normal? Why did it explode? Is it defective?

Make sure to use a brand new needle.
ALWAYS RAISE the presser foot when threading.
Unthread and re-thread from the beginning.
Verify the thread path is correct.
Set the upper tension to midway between High & Low numbers.
Verify the bobbin is loaded and threaded correctly in the bobbin case.
Begin sewing slowly and check the result. The upper tension can be tweaked so the upper & bobbin threads meet in the middle of the fabric.

If it is still not working properly, the machine may be out of time and require service.

...

change the needle to see if that will take care of the problem
if it doens't then the machine needs to be checked at a sewing machine shop about the timing

when you thread the machine make sure to use every thread guide
check to see if the bobbin is in correctly
try changing the needle--normally flat side goes to the back
the needle that your sewing with is it the right one for the thread & fabric
clean under the needle plate & bobbin area for lint or loose threads

Sounds like it is not threaded right, I think you should invest in a new machine. They have them now, where automatically thread themselve. Go to JoAnn's and they will even give you a free lesson on how to operate it. And their prices are reasonable on Singers. Don't frustrate yourself, sewing is coming back and your old machine will be welcome at a community center or sell it in the newspaper. Treat yourself good, because you deserve it. Good luck

the machine may need oiling
check the bobbin area for lint or loose thread
your belt might be getting loose & need to be tighten up

Sounds like you threaded it wrong and kept trying to sew, gently get all of your material out of the machine, DO NOT FORCE, GENTLY ROCK IT OUT OR YOU WILL WRECK THE MACHINE, also watch your dvd and learn about threading from your book. Always, hold your thread ends when you start to sew. If, you cannot find your manual go to www.singerco.com, I have sewn for 50+ years and found that the dvd was very helpful, each machine is different.

need needle threading instructions singer 3116 simple. pictures would help. thank you

hi there
raise pressure foot up thread making sure thread passes between thread guide this should solve problem never alter bobbin tension,
mary h

Your threading is not right, totally remove your thread and rethread according to the manual directions and dvd. If, you still have problems call Singer at 1-800-4singer

Use a SA 156 metal bobbin (ebay, 20 of them for $8.99 free shipping) and make sure the bobbin thread is turning the right direction, read you manual or call singer at 1-800-4singer