PC voltage issues

Hey there.
I’ve run into a bit of a weird one here, so if anyone has a clue what might be going on, I’d really appreciate the help. Basically, I fired up my PC this morning and... nothing. No video signal on the monitor at all. I tried swapping out the monitor—still nothing. Swapped the cable too? Same story. My first thought was, "Well, great, everything just died." So, I shut the whole thing down and didn't touch it the rest of the day. Fast forward to tonight, I power it back up and it actually boots right up. I went straight to checking the voltages to see if things look okay, so if anyone could take a look and let me know if these readings seem alright—or if anyone has any theories on why it refused to wake up this morning—that would be awesome. View on imgur

Those software tools are pretty much useless for voltage readings, so I wouldn't trust them at all. Looking at your screenshots, that 5V rail seems way too low, though maybe the software is just glitching out on you.

Did you hear any BIOS beeps when it failed to boot? What kind of setup are we looking at, and what PSU are you running?

It was acting a little weird at first—lots of questions about whether it would even kick on—but then things leveled out. Plus, that little indicator light by the power button kept blinking and then just completely died on me.

Power supply is an EVGA SuperNOVA
GPU is an AMD Radeon HD 5870

Most likely, your image issues are coming from the graphics card. It looks like you’ve already ruled out the monitor, and honestly, that GPU is getting pretty old...
In a situation like this, it would be ideal if you could test out a different graphics card. You might also want to try installing some newer or alternative drivers.

I mean, yeah... I probably should just grab a newer one, but honestly, I’m a little hesitant to drop money on a new GPU when my power supply is such a question mark right now. I really don't want to end up throwing cash down the drain if the PSU can't handle the load.
My drivers are already up to date, too. The main issue was that my monitor kept going to sleep right in the middle of a game, which is just great.

Thanks for the help.

That PSU is solid and doesn't have a reputation for dying, so unless it's ancient, I guess it’s probably not your culprit.

What kind of beeps were you getting? You usually get a pattern of long and short beeps, which is basically the motherboard trying to tell you what's actually broken.

The computer battery is junk. Swap out the CR2032 for the BIOS/CMOS and you'll likely have it working properly again...
If you know how to use a multimeter, check for 5 volts. Connect the red wire to the black one or the case.
It needs to be 5 volts. It absolutely cannot drop below 4.75v.

That battery's got 3V, so you might have mixed something up there.