First post, by kalm_traveler
So now that I have the rig built mostly, and things are starting to be stable and set up, I decided to figure out why the rear IO USB ports don't work.
I've tried several keyboards and mice, as well as flash drives but nothing seems to work.
Thinking about this, I recalled how pre-3.0 USB only had 4 wires, +5v, GND, and 2 data wires. A quick search reminded me that the two outside pins in an A connector are the +5 and GND pins.
Pulling out my trusty multimeter, I measured the voltage on both of those ports power pins and am a bit surprised by the results... the lower port (closer to the PCB) is ~ 2.05v , and the higher port (farther away from the PCB) is ~ 1.99v
Now... call me crazy, but 2 volts is a lot less than 5 volts. This explains why nothing plugged into those ports is working, but now the question is why would the voltage be so low?
Another interesting quirk is that the USB header on the board works just fine - I connected one of those slot expansion brackets and tested several devices going through the header and it is just fine so there's nothing wrong with the USB controller itself - just something funny going on with those ports on the rear IO...
Any suggestions on what I should look at next to hopefully fix them?
Retro: Win2k/98SE - 2x P3 1.4ghz, 2gb RAM, Quadro FX 4000, Aureal Vortex 2
modern:i9 10980XE, 64gb DDR4, 2x Titan RTX | i9 9900KS, 32gb DDR4, RTX 2080 Ti | i7 7700, 16gb DDR4, GTX 1070 | '19 Razer Blade Pro