Electric discharge to/from case, is something wrong?

[hernands]

I was just arriving home when I tried to turn my PC on and as soon as I got my fingers close to the case it gave me an electric zapp (I guess it was an ESD, since i touched it again and it didn´t zapp me a second time). After that I noticed that my mouse backlight was ON while the PC was off. I had to turn off the power supply and wait for a while until the lights went off. The mouse is working fine, but this makes me think that the discharge didn´t go straight to ground as it should and that I may have damaged other components without knowing.

Is there a certain way to make sure I didn´t damage anything? What are the chances of damaging any components on this type of scenario?? Is my PSU/case faulty for causing this kind of weird issues?? I´ve had problems before with my keyboard and mouse backlight turning on after I turned on my power supply (sometimes I have to turn it off to clean the PC or change a piece of hardware, and when I turn it back on this happens sometimes).

 

[howardp6]

The chances are very low, if your case is metal and most are the static charge would be conducted to the outside of the case and not conducted inside. See Gaussian box.

 

[Saberus]

The zap might not have been from the PC to you, but from you to the PC. With rubber or plastic soled shoes a human can easily and unknowingly carry a fairly hefty amount of charge. As Howardp6 said, the discharges would run along the skin of the box, into the PSU and to the ground lead out to your home ground.

The mouse remaining on is normal, USB ports are often using power from the 5VSB to facilitate charging.