Electric / grounding problem with my Desktop PC?

[Coconut]

If I touch any of my i/o ports (USB, audio jacks, etc) there's like a 30% chance it will crash my computer. More specifically, my display dies ("No Signal") and the hardware locks up (numlock is frozen). My fans keep spinning and my lights are still on, but I have to hard reset to fix.

About a year ago, touching my mouse caused a static shock that fried the mouse and that's when all this started. My current workaround is to discharge any components by plugging them into my grounded laptop first before plugging them into my desktop. But avoiding the problem doesn't solve the problem.

Any advice? I tried reseating and replugging all components, including the standoffs.

[Coconut]

Ursprungligen skrivet av _I_:

ground strap may help, what else are you touching that could be giving you a different charge/ground from the pc?

I don't think I'm touching anything that could be a different ground. I sit in a cloth chair with a wood desk. Computer sits on the desk too. Floor is carpet, which I know contributes to static buildup. But I can discharge myself to avoid killing the computer by touch.
However, plugging things in will still trigger the problem even if I'm careful not to touch anything conductive. For example, I can trigger the problem by plugging in my headphones, even though the plug is coated in plastic and I handle it by the plastic. So I don't think it's anything I'm touching specifically.

[_I_]

then its most likely just static due to walking, gaining/losing electrons giving you a different charge than ground

rubbing stock on carpet is enough to do it

if the room is very dry, a small humidifier is enough to solve it

i got one like this for my dad
https://www.ebay.com/itm/1L-USB-Electric-Mist-Air-Humidifier-LED-Ultrasonic-Aroma-Diffuser-Essential-Home/143568017439?hash=item216d52181f:m:mNPMX05xQ6-RtwuwMN2UInw
works good, usb powered, draws under 1a, old phone charger works great on it, goes 2-3 days before needing to be filled again

[x_wing]

If the static is generated by the OP, he can try to touch a ground connected metal (like a nearby radiator or the bathroom/kitchen tap) and then touch his i/o ports. If the reboots go away in the 100% of the times, then it was him all this time :P

Anyway, I would still check the build (remember to ground yourself while doing this!).

[Bad 💀 Motha]

Does your bios have an anti-surge option? Disable it.

[Talby]

Ursprungligen skrivet av countofcounts:

Ursprungligen skrivet av _I_:

ground strap may help, what else are you touching that could be giving you a different charge/ground from the pc?

I don't think I'm touching anything that could be a different ground. I sit in a cloth chair with a wood desk. Computer sits on the desk too. Floor is carpet, which I know contributes to static buildup. But I can discharge myself to avoid killing the computer by touch.
However, plugging things in will still trigger the problem even if I'm careful not to touch anything conductive. For example, I can trigger the problem by plugging in my headphones, even though the plug is coated in plastic and I handle it by the plastic. So I don't think it's anything I'm touching specifically.

I would remove the motherboard and take a note of the I/O shield itself, could be one of the grounding tabs got jammed up somehow in a bad way. Might as well double-check the mounting screws and make sure nothing is grounding out while it's out. If you have an extra AC power cable for the PSU, why not swap it out all the same.

[Coconut]

Ursprungligen skrivet av Talby:

I would remove the motherboard and take a note of the I/O shield itself, could be one of the grounding tabs got jammed up somehow in a bad way. Might as well double-check the mounting screws and make sure nothing is grounding out while it's out. If you have an extra AC power cable for the PSU, why not swap it out all the same.

Thanks. I didn't know those tabs were used for grounding. I think a couple of tabs are actually broken off completely (not on purpose).
--

Based on multiple responses it sounds like a teardown & rebuild is inevitable. That'll have to wait till next week though. Appreciate everyone's help!

[_I_]

the io shield is ground, but not needed to ground things
its needed to prevent objects or dust from entering the io area

the mobo has lots of grounding locations (each of the screw holes are grounds along with several on the eps 4+4 and 20+4 power connectors, usb/audio headers, and sata data ect..)

[Jamebonds1]

Ursprungligen skrivet av _I_:

the io shield is ground, but not needed to ground things
its needed to prevent objects or dust from entering the io area

the mobo has lots of grounding locations (each of the screw holes are grounds along with several on the eps 4+4 and 20+4 power connectors, usb/audio headers, and sata data ect..)

Shield backplate is needed, so ground does. If ESD hit the port's metal case without a shielded backplate, severe damage to the motherboard can occur. Some people think ESD flow through the port case's metal sheet will not be radiated, it can. It is called a coupling plane. That is why shield backplate is essential.

[_I_]

if any shock/lightning hit the io area with enough to damage it, the io shield would not help

[Jamebonds1]

Ursprungligen skrivet av _I_:

if any shock/lightning hit the io area with enough to damage it, the io shield would not help

It is better than without shield backplate. I know there is a margin level test that the compliance team in some manufacturers won't tell anyone. Some passed the margin level test, and some don't. The margin level test is 10 kV to 20 kV ESD testing. My reviewer would have a long list of reasons why a margin level test is critical. ESD and surge will hit PC a few times, and lightning causes surge is least common.

There is a standard for ESD, but it is expensive.

61000-4-2 [global.ihs.com]

C37.90.3 [global.ihs.com]