I found a screw just laying there!

[Juli in Kona]

Looks like it fell off the machine (Amaya XT). So I looked on the back of the needle head and right behind the active needle on the back side, there is a metal trapezoid with a hole in the middle. I can see inside the hole (can't fit my hear in there) but when I try to fit the screw in there, it does go in. Is there supposed to be a screw/washer in there?

I have just recently been experiencing thread breaks on a straight simple single line center. Shouldn't have thread breaks there! AND tons of thread breaks on text.

[Greenwing]

Juli
there are three headed screws there.
1 on the right that holds the bottom corner of the right side front black cover plate on.
and 2 on the left hand side right next to each other the other two holes have what looks like set screws in them.

but there are 4 screws behind there that mount the thread retaining bar that the sweeper tucks the thread in colud it be from there?