General Tools Center Punch type 77
I took my center punch apart to clean it, and it stopped working until I reassembled the components in the correct order. The most important thing to know is that the cylinder spring on the left near the point must be assembled with the flat end towards the point and the curly end towards the body; this offsets the T-shaped "anvil" off-center so it pops into the cone end cylinder on the right, making a "snap" impulse.
There are a few poorly-designed low-contrast youtube videos that allegedly show the assembly, but the components appear black and are mostly hidden by the presenter's hands. I hope this simple picture and text are understandable.