Knitting machine help!

Hi,
I have been knitting by hand since I was 6 years old. i have recently become interested in producing knitted items at a faster speed than I can hand knit. I have a knitting machine (an old studio700) and, although I have all of the manuals, I can’t figure out why certain things are going wrong.
One problem I am having is with the lace carriage. when I cast on, the first and second rows come out prefect, but the third row does not complete. sometimes it is just the last three or four stiches that are incomplete, but sometimes there are incomplete stiches dispersed along the entire row (about 8 inches long). It is like the machine doesn’t catch and complete the new stich, it just catches it.
Does anyone know why this is happening? Or how to fix it?

I learn very well through experience, so I have kind of just jumped into this, but I can’t figure this problem out.

Thanks!!!

I had the same problem on my 700. The most likely problem is your sponge bar (called the needle retainer in the manual). This holds the needles down and is the most common cause of machine knitting problems. To check your sponge bar, insert a pencil into one side of the machine and pull the bar out of the other side. There should be about 1 cm of sponge. If it is flat, this is most likely your problem.