The blue spark was probably static and should have grounded out through the monitor frame. I wouldn't expect any problems.

As for the other issues, there is obviously some voltage changes happening in your household circuit. The Power Supply should absorb minor changes, but that will burn the PSU itself out pretty soon.

Easiest solution (aka, not rewiring the house) is getting a Power Conditioner or Universal Power Supply. Should be 100 bucks ish. Well worth it to protect your hardware if you suspect dirty power.

I think you're over reacting to a point that you're not seeing things clearly. If nothing's wrong don't go looking for something. I'm not trying to come off as a dick, but it really doesn't seem like there's an issue. The line could have easily been a capacitor charging up, and trying to replicate it didn't work because it already had its charge.

It's probably not a problem.

If it's worrying you, get a small UPS for each computer. The controllers for them have gotten much cheaper, and better in the past few years. Even the bargain model will probably have some automatic curettage regulation. This will protect your computer from momentary (to fairly short) dips in power, and for power outages laying maybe ten minutes. That is plenty. The bigger more expensive units give you more time on otherwise identical equipment, or the same time on bigger equipment, and you won't need that. The batteries are cheap crap in anything you can afford, and will all wear out in a few years.

>>917252
I bet you live in America and aren't using grounded outlets.

With no true ground, the 0v of any PSU floats to whatever it likes; usually some approximation of ground potential.

Each PSU, however, will float to a different ground potential. if you join the grounds of two different PSUs together (with a DVI cable, for instance), current will flow from one to the other as the ground potentials equalise. It's the initial potential difference that causes your spark.

With a true earth (or even the earth pins in the outlet tied to each other and floating), every PSU's 0v is already tied to the same socket earth, so when you plug two devices together, they're already at the same potential, and there's no sparking.

Double-insulated (two-wire) home electronics is notorious for this. The original Xbox ground could float to voltages where it really frickin' hurt if you managed to touch the (carefully shielded) case ground. If the Xbox was connected to the wall, but the AV wasn't connected to the TV, and you happened to touch it, you'd know.

>>917252
There is literally nothing wrong here. You just experienced what happens when a double insulated device is connected to an earthed device. Your computer case is earthed but your AC powered peripherals will be double insulated, meaning basically it has two layers of insulation between all AC components because it does not have a metal case to ground to (or if it does, it is not tied to earth on the power point)

The spark (or bite you'll feel if you're touching the case and the sheath of a DVI port) is simply because the peripheral has a "floating earth". Relative to the circuit of the monitor, that metal shield is ground, but relative to an actually earthed device there may be a slight voltage difference. You can verify this by unplugging your monitor from AC and verifying no spark when you drag the DVI shield across the metal of the case. Reconnect the AC to the monitor and the spark will be back.

Expect to see this to some degree on any device that is powered by an AC brick or a 2 wire AC cord. Nether will be directly earthed, and both will float at a voltage higher than an earthed chassis. There is no risk of shock or damage here, it's been a problem since the first brick powered LPT printers, and apparently it's not going away for whatever reason.

Of course, had you have googled "spark between monitor cable and computer" you would know this already, and I wouldn't need to tell you to fuck off and read the sticky. This is a common problem, and not worth a thread.

>>917374
The issue can be replicated and is consistent with the powering on/off of the computer. Exhibits the same symptoms I outlined in the OP (loss of signal or a white static line across the screen).

>>917382
>>917387
Thanks, that takes care of the dvi spark.
There's still the issue with the monitor though, not sure if it's a problem with the screen or the video card.
Although if it's a voltage dip/spike then I think it has less of chance going through the PSU into the video card, and more of a chance going through the power circuit in the monitor (correct me if I'm wrong though, I have a pretty basic knowledge of electronics).

>>917252
>When flipping the psu power switch to "on"
>flipping

Why are you doing this? The ATX standard exists so that you don't need to do this, and the computer can wake itself up when it needs to, and you don't needlessly run down your clock battery.

Anyhoo, shitty DVI leads plus contactor spark equals desync caused by EMI.

Turn your computers on and off properly, stop using physical mains interruptors. They're computers, not lightbulbs.

>>917546
>issue can be replicated
Not what you said in the OP

>>917656
>either losing signal or having a small static line appear on it
Two different symptoms imply the issue was reproduced at least twice.

>>917658
Two different symptoms also imply 2 separate issues. And you're implying that there's even an issue to begin with.

>>917676
Unlikely that two seperate issues would be triggered by the same thing.
One issue, manifesting itself in two different symptoms.
I don't see why my post was hard for you to comprehend, maybe I wasn't completely clear but everyone else seemed to have understood what I meant.

>>917761
Because you said you couldn't replicate the issue you dolt, and then you said everything was working fine afterwards.

>>917800
>I switched between the monitors and sure enough I couldn't reproduce the issue.
>I switched between the monitors
>switched
>monitors

Maybe you should use a tripcode, so next time we'll all know to use small words and repeat ourselves until you understand.

Anyway this thread is dead, thanks for the help guys.