Gen 3 V1c 5V/-5V weirdness and clicking noise double-check?

[angusmf]

Sorry in advance for the novel:
I ordered five gen3 (V1c) block 3 boards from JLC and have been working to get one assembled and working properly. The main problem was the -5V charge pump components were from the previous design. After replacing those--carefully, at least on my very last board--I finally did one that tested out ok for all voltages (5V, 3.3V, -5V, 26V.) I tested the voltages over and over and over--each time a new component, header or connector was added to the board. At some point when nearly done with all that, a low-frequency ticking noise appeared. It's pretty faint, so it could have been there all along, but I definitely didn't notice it until the board was pretty much populated, and I did simple stuff like connectors and headers dead last. The first board I built (with the messed up charge pump stuff) also clicked like this. All the voltages still looked good with the possible exception that the -5V was a tenths or so higher (so 1.x tenths fewer negative volts) than I expected. 5V was reading about 5.07V, -5V gave more like -4.9-ishV.
Later, after a full day spent getting the wifi board (hopefully) programmed, I plug it all back in and see the 26V rail is the same, but everything else reads a bit lower. 5V is at 4.9V, -5V is at -4.8, 3.3V is now about 3.28-3.29V. It seems at least partly to be dependent on the supply voltage, such that increasing it from 12.5 to 13.8 pulls those voltages back up. Changing the current limit does nothing--it's already sitting well below what I had it set for. The board has since been cleaned with isopropyl alcohol but that didn't noticeably change anything. Neither does adding or removing a bootstrap cap to the 5V buck converter chip.

So my multi-part query is, should I worry about any of:
- the -5V voltage being a little "high"
- the slight dependence on the PS voltage
- or the clicking noise?
Hoping they all do this, but it's been such a frickin' struggle to get this far, I'm paranoid now, and a board that makes noise is just a lil spooky. I'm asking "my" EE what he thinks, but it would be great to also hear reassurance or dire warnings, as the case may be, from someone who has assembled one or more boards. Thanks!!!

[angusmf]

Previously on "Clicky Noise WTF?":

- Programmed the main micro with the sine software
- Tracked the noise to somewhere near the 3.3V (LD1) regulator. That's also near X1, which appears to be an external clock crystal. The clicking noise is NOT in the MHz range, or I wouldn't be able to hear it, though.