Brother 840 punchcard gate peg problem?

Hi,
There are three points to check to rectify this problem.
Check your tension on the upper tension unit, it may need tightening slightly.
Don't move the carriage too quickly when you change direction, the yarn needs time to be taken up by the spring.
Check the wheels and brushes on the sinker plate and remove any yarn that is stuck in them. If there are any stray bristles that could catch the yarn snip them of with a sharp pair of scissors - don't pull them out. Some people remove the outer brushes and find that solves the problem.
Hope this helps,

Sue
September 2013