Re-assemble everything back in the same order of disassembly. Be careful when connecting the flat flex cables. It is very easy to damage them.

Test the camera. It should work now, but in case the error persists, try moving the spring adjustment wheel for one or two clicks more.

If it still doesn't work, you may need a new shutter assembly. There are plenty on sale, you can find it if you look for it.

Good luck!