Wheel truing is an iterative process. The "chinking" noise is where the spokes cross and they are moving relative to the other one.
I'm guessing you trued the wheel but the spoke tension had not been relieved - and when it did relax, the rim went a little more out of true.
The fix is to stress the wheel sideways somewhat, by:
- Gently laying it on the ground and press opposite sides of the rim
- Ride it a little
- Grab pairs of spokes in your hands and give them a solid squeeze.
...and then to continue with the truing. You also want to check wobble, vertical displacement, and spoke tension. Alternate around, working on the worst thing to make it better but not perfect. There's little point in fixing one area of the rim perfect, then adjusting another bit which puts the first bit out of whack.
Another gotcha with using the brake pads as a truing reference is that the rim may not be consistent width. A rim that has taken an impact may be bulging or widened, which can put your measurements off.
Truing with the tyre on can also make it harder to get that very last bit out. For a quick improvement its fine, but to do a really nice wheel you want the tyre/tube off. Some people will even remove the rim tape.