Voltage drop and (malfunctioning?) USB controllers

[diegzumillo]

Hey all
I don't know if this would be the forum to ask this but here goes. So I was testing my system and noticed current drops, the icon blinking at the corner of the screen. Not enough to restart the system but enough to make me concerned. Then I turned everything off and on again, and the problem went away.

So, the problem not being easily reproducible makes it hard to diagnose. The reason I think it's the USB controller is because I just finished soldering wires to its PCB board. Before that never had any problems. Also, using a multimeter tells me the voltage across this board is constantly increasing ever so slightly! (edit: it seems to reach a maximum value and stay there) I don't know if that's normal behavior. I have it on right now to see how high it gets and see if it's going to start dropping the voltage of the Pi.

All the buttons work just fine though. I imagine that if I botched the soldering process I would see the effects on the funcionality of the controller, like a button constantly pressed or a button that doesn't work etc. But no, everything works fine. Could this still be a soldering problem? Maybe a couple of solder drops barely touching each other or something like that?