Update: I made the slanted area that the spring touches a little thicker, meaning there is a little more force applied to the spring and this makes the dust cover less likely to droop down when in the open position. Use version 2 of the design.

This a replacement hinge that fits into the original spring mechanism used on some Technics turntables. It functions exactly like an original hinge and there is no need to drill holes in your dust cover or plinth.

Print at 0.2mm layer height, 4 top and bottom layers, 4 perimeters, 100% infill and a 2mm brim. The brim is needed for the tiny piece in the middle (or glue stick might work, have not tested). Since this will be under constant pressure from the very stiff spring, I would not go lower than this.
I printed mine in PLA but most materials should work.

MATERIALS NEEDED
x1 M3x16mm or longer screw
x2 M3 nuts

TOOLS NEEDED
Drill/drill press and appropriate size drill bit
Small flathead screwdriver
Dremel/rotary tool with cutting wheel

INSTRUCTIONS

1. Drill the rivet out of the broken hinge so you can disassemble it. DO NOT drill through metal bracket the rivet sits inside.
2. Measure the screw length and mark it at 15 or 16mm closest to the head of the screw.
3. Put the 2 nuts onto the screw and clamp it into a vise. The nuts protect the threads of the screw from being crushed in the vise.
4. Use a dremel tool and a thin (1mm or thinner) cutoff wheel to cut the head off the screw. You may need to cut off some extra to get between 15 and 16mm of thread.
5. Use the dremel tool again to cut a slot into the end of the screw.
6. Use the flat part of the cutoff wheel to clean up any sharp edges.
7. Put the two nuts into the printed part and put the spring mechanism onto the part as shown.
8. Use a small flathead screwdriver to screw the thread into the two nuts and through the printed part. The thread will hold the metal bracket in place. There should be minimal extra thread showing on either side. If there is too much thread, it won't fit back into the turntable.