Sewing machine help

[Alicay]

My DD has just got a Brother RL417 & is having problems with stitching. I don't know anything about sewing machines & haven't been able to help.
She says the problem is on the underside of the fabric (regardless of stitch) when she starts to sew the thread on the underside starts to tangle and leaves loops rather than stitches. Have prob explained badly.

Any idea what's going wrong?
TIA

I would guess the bobbin is not correctly threaded and check the spool threading as well.

Tension most likely.

Has she totally rethreaded both spools and double checked all is correct?

Thanks both, did as advised & (kind of) going OK. It's woman v sewing machine at the moment though - am going to watch a few YouTube videos & educate myself!

Has she checked the thread tension is adjusted to the right point for the stitch she is trying to do? There might be a sliding button somewhere. In the manual that comes with the machine there is usually a summary of what you need to set it to

Hi i have a brother sewing machine and had similar problem so i adjusted the tension and it was all fine.

Thanks! Slight problem is we have no more thread and all non-essential shops are shut in the country we live in. Regretting not stockpiling