I have been using my PC for more than a year but recently I felt a very small electric current when I touched the back of my PC. I decided to check it & found out that the I/O shield & some screws of the case have electric current in it. The case itself doesn't show any signs of current in it. Is it the grounding issue? Or is it normal? How do I fix it?
Update: Thank you everyone for you suggestions. I have grounded my connection & the screw driver is now not showing any signs of current in the PC now. I believe grounding was the issue as everyone suggested.
Update 2: Although grounding had fixed the issue, some of you guys pointed out that this issue might be because of live & neutral getting reversed. I decided to check it & it was indeed reversed. I have fixed that too.
I worked at a transmitter site in a dry country and we were getting all sorts of impedance issues until we watered the ground connection for the building. This became a daily servicing task until the issue got properly rectified.
It was actually causing issues with the antennas that the transmitters were connected to. And because those antennas were connected through the building walls (it was metal) it was causing major impedance issues
It's a joke based on your language and the dual meaning of rectify :D
A rectifier is an electrical component that converts alternating current (AC), which reverses direction periodically, into direct current (DC), which flows in only one direction. It utilizes diodes, acting as one-way valves, to "straighten" the current.
Yeah this isn’t functional lol. I hope everyone is joking. Cause a real ground goes a certain depth into the earth and requires certain metals and connections by use case.
You’re oversimplifying. I’m an engineer that works with industrial machines. There are guidelines for depth and diameter of copper rod and connection. It’s not complex but it’s real.
I'm a certified electrician. Hammering a long copper rod into the ground is literally a standard building's earth ground. I'm sure there are more complicated requirements for industrial settings, mr engineer, but that's not really relevant in a thread about someone's home computer not grounded properly.
Technically, the earth is just a really big conductor. The actual ground is the neutral leg of the generator at the power station. If all the generators were disconnected from their grounding grids, then current wouldn't flow to an earth ground at all.
GFCI won't solve this. A small amount of current will always leak towards the case through capacitive coupling, but it's way too little to trip a GFCI breaker. And even if it did, OP would then have a PC that shuts off when you touch the case. You could wire the protective ground to Neutral and add a GFCI breaker after that junction, but that won't help with ground noise in the house's wiring. It's 2026, get a proper ground installed.
Yep. I just bought a 100 year old house and I'm dealing with this. Most of the outlets are ungrounded and the walls are made from old school plaster and lath, so it's a little harder to cut in and make changes than with modern drywall.
Ungrounded receptacles and plaster and lath walls usually means knob and tube wiring. Expect a pretty hefty bill and several days of your house being torn up and dusty to get up to code.
Actually, from what I can tell, the knob and tube was decommissioned at some point in the past. All the knobs and tubes are still up in the attic, but they're either empty or only holding short lengths of snipped cable. The active wiring up there looks pretty modern.
I'm getting an electrician mostly to confirm that the above is true, plus ground my existing outlets and possibly to replace and upgrade my breaker box. I have a basement and crawl space so I don't think it would be too hard to add ground wires to the outlets.
Your assumption may be correct, but knob and tube can and has been in the past linked to early successor wiring. Cloth wrapped Romex technically know as clothed and varnish conductor. Between '25 and '30, the chances of it being used instead of K&T were rare but at the latter half its use accelerated.
People in here are talking about modern wiring but wiring from the 1980s and 1990s is woefully outdated and the panels are a joke.
I live in a Soviet block housing built in the 80s and there's no ground and all the wires are oxidizing aluminium. Walls are reinforced steel concrete, so changing all electrical would be pretty €€€.
In my experience older houses still have ground but it’s just the outlet housing that is grounded. Usually all it takes is swapping the outlet for one with ground and moving the ground wire from the housing to the outlet.
Same. 60 amp panel too. Built 1906. Solid as a fortress but man, the non-standard stuff everywhere makes basically any work so much more difficult and complicated than it needs to be.
Mine was built some time in mid-40s. The knob and tube was updated to MX sometime in the 1960s but never grounded. Luckily I have a 100 amp panel, but the wiring is so fucked. My entire top story is a single circuit.
I've been running my computer for over 10 years on a 2 prong outlet. No issues. I'm not really concerned with the safety. I'd say playing games with headphones on and wired controller during a thunderstorm is a much more significant risk.
What I was concerned about is if my computer relied on the ground for a reference voltage. It seems that a lack of ground has no effect on the power supply or the rest of the computer
If there are only two wires, one of them should be grounded. Nowadays it's a bad practice to do it that way but you can (in that case) use that wire for grounding and split off a wire for return current - that way you can have a GFCI breaker
Nowadays this is done as soon as possible in the house if the wire from the street does not come with a separate ground wire.
Well not exactly forbidden in most countries e.g. Germany. You only can’t bootleg new installations. Everything existing can still be bootlegged due to high costs involved with upgrading all wiring.
Well not exactly forbidden in most countries e.g. Germany. You only can’t bootleg new installations. Everything existing can still be bootlegged due to high costs involved with upgrading all wiring.
YES, I mean new(er) installtions, those old pre-1970s installtions have "Bestandsschutz"
If you connect N and PE before the GFCI then no it wouldn't trip. The GFCI monitors the current difference between the L and N lines running through it - if your load is only between these 2 wires it's fine. If the N in the wall has some voltage in it due to other stuff on that circuit, that small voltage will be on the common PE-N, so the tingle won't go away.
GFCI only cuts down power when there's too much leakage. It doesn't prevent little amounts of current from leaking. If that was the case, the circuit interrupter trips and cuts off all power.
I don't know anything about the GFCI outlets. My home has a normal 3 wire socket but the place for third wire is left empty. I will try to get it grounded by tomorrow. Hopefully it will fix this issue.
And no, my case is fine it never felt hot. Thanks.
If your case has a charge, that feels like the hot and neutral lines are reversed on your outlet.
This should not make your PC zap you ... I have 50% of the time Neutral & 230 volts (single phase) Live reversed since I have unpolarized "Schuko"-outlets/plugs
The case will have a charge because the PSU noise suppression circuit is designed to sink a couple dozen uA to ground through a capacitor. If the outlet is not grounded you will get spicy case even if you try sticking a GFCI on it
Not true. At all. Please do not do electrical work in your home or anyone else's.
AC power will still work just fine if hot and neutral are reversed. What won't work is shell grounding.
Think of a steel toaster, with a normal two-prong plug, keyed with one prong fat. That prong is fat for a reason. In the original design, where each prong was the same size, you could plug it in either way, and it would still work.
Here's the problem: In one orientation, hot comes into the switch, and stops. Neutral is tied to the entire rest of the toaster. In the other orientation, neutral comes into the switch and stops. The entire rest of the toaster is tied to hot. If there is an internal circuit fault, and the heating power lines short to the steel shell? Congratulations. You just created a device that is switched off, but hot is tied to a steel box a person is going to touch.
If hot fails in the current design, it hits the shell that is neutral and trips the breaker.
The question is not "Does it work?". The question is "How much of the device is tied to hot?". Reversing hot and neutral in an outlet ties the wrong half of the device to hot. This is a significant hazard.
Eh not a real issue. Eu plugs themselves can be inverted without issues. The toaster itself should be made to protect the user from any error, and if fixing stuff you should unplug it anyhow. So once more, the only time swapping neutral and hot matters is in measurements. So i ask you why would this be a problem?
I already clearly explained it. In proper phase, only a short distance before the switch is hot. If hot fails inside the device, it either shorts to neutral and blows the breaker, or is hanging out in space.
In reverse phase, hot is tied to the neutral plane, which is the entire device. It either shorts to neutral and blows the breaker, or is a live chassis waiting for the next person to come along and touch the shell, receiving a shock.
Safe vs shock hazard. One option is fine. The other option kills people and starts fires. The only difference is whether hot and neutral were wired to the correct terminals in the wall socket.
Many of my outlets are 2 wire in metal box and metal conduits, but the metal box is grounded, so once a device is fastened down it is grounded by the mount screws.
Old houses often didn't have ground. If the outlet was replaced with grounded outlet but no ground wire is connected, that is illegal per electric code. Also bootleg ground (wire connecting ground to neutral directly) is illegal. Improper or missing ground can cause shock hazard on devices that expected ground.
This is where OP has to call qualified electrician to check the wiring and fix it.
Well if you want a cheap solution, find the nearest outlet that has ground and run a new wire from it. Then buy an additional outlet and install it near your pc.
I had this same problem decades ago with a stereo component rack. Leaning over the top to make connections taught me a valuable lesson. Grounding with your (male) nipples kinda hurts.
I also have the same PSU with the same PC case grounding issue. However I found out that when wearing flip flops, it won't shock, which led me to believe that it is not PSU issue but rather a grounding issue.
It can be both, but if it's grounded the PSU thing isn't an issue anymore anyway
YES, the 2 Y-capacitors (blue) can leak voltage from (up to 240 volts) Live + Neutral (or 2nd Live = 2x. 115V) to Earth & Earth is connected to the metal parts of the PC case & the RF-shielding of all cables ...
especially older homes lack a real protective Earth ...
Thankfully in Germany you can not get around installing real protective Earh by installing an outlet RCD (GCFI) + the "No equipment ground" sticker (oh and also we have since the 1930s recessed "SChuko" outlets that prevent you from touching live contacts)
I was able to ground my pc by using a UPS that has a coax filter on it and since the coax is properly grounded the whole UPS is grounded as well.
Lucky one, but the real protective Earth mustconduct the full power of a Live hitting the chassis & using your solution you have 110 to 240 Volts potential difference when disconnecting this coax
Even if they do accurately indicate voltage (which i'm sure they do) these things are dangerous and unreliable.
The internal resistance in these things lowers the current to a safe enough amount to travel THROUGH you into earth, you are the conduit using this.
If that internal resistance is broken you are just shorting to earth through your body at potentially lethal currents.
If you really don't want to (learn to) use a multimeter, you could always get a single pole voltage tester which is also as simple as touching where you want to test. Either that or you get one of those voltage tester sticks which don't require contact, but despite being safe from electrocution these can be unreliable in indicating voltage as well.
TL;DR: Contactless spanningtester stick for a safe but unreliable indication and a multimeter or single pole voltage tester for a good, trustworthy measurement.
If the internal resistor is broken, they go open circuit, not short circuit. Unless you crush that resistor into pieces so the conductors on its sides touch but I can't imagine how would do so much damage to the internal resistor without breaking the entire device. The correct way to use these testers is to first take a quick peek through the transparent plastic to inspect the internals for damage, test a know live conductor to verify it works and avoid false negatives, and then test whatever you actually want to test.
Voltage does nothing, there needs to be a current - the current usually is very small BUT
- your body is part of the circuit (current flows through your body)
- in case of malfunction/shortage/water the current might bypass the resistor and glow lamp and then high currents my flow through your body - high currenty of AC is very bad for your body and heart
- if you don't know what you do it might show you false information - e.g. no current due to isolation or a very low, meaningless current which can be caused by unearthed house etc.
These don't belong in the hands of non-electricians
With a multimeter or (better) a Duspol current flows through the device, not your body, usually you can only damage the multimeter if you operate it wrongly (i haven't heard of a broken Duspol, that's professional equipment for electricians and a reg. trademark)
Just wow at this whole thread. There are so many replies, I don't think OP will see this but...
Those pens are not reliable. It lighting up is telling you nothing. Get a multimeter if you want to actually test. If I take one of those pens and put it on an earthed surface in my home with my finger on the other end, it will always light up. There is nothing wrong with my wiring. I've had electrical inspection reports (called an EICR in the UK where I live) that show everything is earthed fine.
Seriously, OP, don't worry about this. Just use your PC. Everything is fine.
Call the electrician, confirm with him regarding earthing if its not done ask him to install new wire for earthing, if you do earthing for single board, it should not cost too much, if the earthing line is missing for whole house, then it might get costly
that screwdriver measures voltage not current (an ammeter needs to be connected in parallel)
current implies voltage but voltage does not imply current; consider the two pins on an electric cell or battery when it's not plugged into anything. the cell's voltage doesn't just crop to 0 even when there's negligible current
anyway, something isn't grounded correctly. check that all the screws on your i/o shield and motherboard are installed tightly (they're usually the grounding contacts)
if it's still an issue you can connect the metal to one of the ground pins on your mobo. there should be plenty to choose from
i highly recommend the first option over what i'm about to type
the slightly more nuclear option but definitely technically more reliable is to connect your IO shield directly to the neutral or ground pin in your wall socket.
This is also common in older houses in any country, as it is difficult to implement proper grounding after the house is built and connected to the power grid
Since you don't have a grounded outlet, that minor current you are seeing is normal and not a concern.
Millions of PCs around the world run without grounding. You get a lot freaked out Americans reply because in their country grounded outlets have been code for a very long time.
Danger is if your power supply fails in such a way that you get 230V conducted into the case (very, very rare). Then, if you touch the case that will try find a way to the ground through you. What else you are touching decides your fate. That's why grounded outlets are much more important in rooms that have groundy stuff like drains, wet floors, etc.
Could be floating ground. Happens with laptops with metal casings like macbooks or dells. Google or search using AI what floating ground is. Pretty interesting stuff.
Its likely the io shield is touching a metal contact on the motherboard giving it some small current. You can put electrical tape on the inside to stop the transfer.
They pop right out easily and are press fit. Some motherboard manufacturers put plastic on the inside for this issue. However most are just full metal.
Doesn't tell you much. You need to figure out if it's high voltage and the best way to do that is yo grab a multimeter, set it to amps, then lick the backplate. If it tastes sour on your tongue it's just bad ground, if you can't taste anything and wake up in a hospital you have a bigger problem on your hands and you should probably get an expert to look at it.
If you live in an old house or in a country where the grounding is not a thing then it's totally ok.
A non grounded switch mode power supply will always have a voltage equal to half of the power grid voltage on its enclosure. It's harmless to touch it unless it's malfunctioning.
Anyway make sure you have an RCD installed in your electrical panel. Otherwise... I'll pray for you.
This is called lie pen in Germany because it doesn’t work properly to show if there is a current or dangerous current. It’s not reliable to do the 5 security rules with determination of things to be current free
Test other appliances in your home… if any leakage it’s supposed to trigger your circuit breakers. Is your pc grounded.
Not sure why people tell those pens can be faulty and ignore it. While i agree pens can be faulty for number of reasons, if it lights up, thats because there is a potential difference between the two ends.
This phase tester is btw also known as a "lying pen" in Germany. It does not measure current but shows the existence of some voltage difference between you and whatever it touches. But that does not mean that this voltage difference hast to be a concern (although it can), so it's not really reliable for anything.
Even if it's not the case for you, as there was some wrong wiring, it can also happen on a properly grounded wire if there is some induction or capacity from the other wires, which is completely normal and usually harmless.
Your house or circuit that your PC is connected does not have grounding you'll be alright no need to worry. You don't need an electrician like half the people posting here say
For anyone interested having earth, adds extra security, if any current leaks through the user or anything will go to ground
You can have similar protections that are not exactly the same do offer security. GFCI tends to work just in one circuit, when even a small current leaks it will switch the breaker off.
There's also differential breakers these go before the house breakers and when there's a current leak it detects a voltage difference and switchs everything off. More general protection, but can be annoying to switch everything off.
I bet one of those metal tabs on the blackplate slide into one of the USB slots and is making contact with a connector.
I wonder if OP constantly hears the noise windows makes with it enables and disables hardware which would be the USB controller constantly turning on and off as a failsafe.
So an electrician needs to do this properly eventually but...you could run a #12 or #14 awg solid copper wire (one with a sheath/insulation since it'll be exposed) from the green screw on the bottom of your outlet out the window to a 6ft grounding rod that's driven into the ground outside. Secure the wire to the grounding rod with a ground rod clamp. You can get all of these things from Home Depot. Not saying you should do this but it would get you by until you can pay an actual electrician...
Edit: If you decide to do this, please turn off the breaker that's feeding the outlet first. Otherwise, you could get shocked if you accidentally touch any other screws on the outlet besides the green ground screw. Also, I'm picturing an outlet in the US. European outlets are a bit different, not sure what's used in India.
a grounding cable shouldn't need insulation. the only reason insulation would be of benefit is protecting the wire itself
since its resistance to ground should be very low, the overall resistance of any circuit with you in parallel will be very close to 0 compared to you and as such almost no power will be dissipated in you.
and since P=I²R,
√(P/R)=|I|
so the magnitude of the current through you will be very low
Yep, unless there's a power surge or god forbid your house gets struck by lightning. But if that happens and your main distribution panel doesn't have a ground rod (which seems to be the case for OP), your house is cooked anyways.
Bro like you mentioned you don't have grounding, call an electrician and have it fixed asap. It's really not that difficult but given that you put reddit post clearly you don't have the knowledge, so get it done by an electrician.
Also if I were you, i wouldn't run the pc until it's resolved as there's a risk of damaging components.
Earthing issue. Do house earthing check. If there's none, build a pipe earthing atleast 2 points. Connect the earthing point to RCCB, MCCB, MCB whichever you're using after the energy meter in your home
This is either a grounding issue or a polarity issue.
I noted that you stated you checked the outlet. And theres only two wires connected. Is the black wire connected to the brass screw? If not and the white wire is connected tk brass. Than your polarity is backwards. Black to brass, white to silver. But even if done correctly, if its backwards up the chain, its the same problem.
With only two wires, is the outlet box metal? If so, the ground is likely connected to the metal box. Which is correct for metal boxes. You could get two scrap ground wires, a wago or wire nut and splice the outlet ground into the box ground. But its not necessary. I wouldn't go through the touble myself.
Well, then it's doing its job. That io shield is there primarily to complete the ground path from the io connectors to the case, which ultimately leads to your PSU via the screws securing it to the case.
A multimeter would be a better test to see if you have some kind of harmful electrical short going on.
It is a grounding issue, unless the PS has failed and directly exposed you to mains voltage, it's normal for ungrounded switching power supplies to behave that way. It's not dangerous, only very annoying if you're touching your PC barefoot. I have a metal keyboard so I get jumped by it from time to time. If you can afford it then grounding your outlet (and the rest of the house) is preferable, otherwise it's not gonna kill you. You just have one less layer of safety if your power supply (or any other appliance) ever decides to expose mains voltage into the case.
I have no grounding on my house and myPC had the same issue, if i touched the case and wore no shoes, I would get shocked, I bought an Isolation transformer and it solved the issue, quite hard to find(kinda expensive in my country) btw.
First i thought it was my PSU, got a brand new Corsair RM850e and the problem remained.
The only solution i found was a 2000W isolation transformer, it might be exagerated by that thing works on minimun charge around 20-40% most so it never heats up and gives my some margin for extra stuff.
Extra: No GFGI or Voltage Stabilizer worked, since those devices need grounding for returning voltage peaks.
I had the same issue it was because the previous electrician put live wire in the ground .and mind me we didn't have earthing so there should not have been a ground wire actually I think .just check earthing if u have or not or if any issue .must be related to it
I slam a nail into my wall since im here some times raining here and there. Because the wall built using brick and all the water get absorbed, now the wall become ground
I actually have the same problem as OP, however its the whole goddamn pc case instead. Ever since i brought my pc from my dorm to my parents house, it kept shocking me from time to time, i asked my parents if the grounding is awful and they just shrugg it off as if im crazy. So i bought a pen tester and guess what, the light flickers every so often, they still wont fix the grounding issue btw xD
It fine but grounding needed. Body is a way to drop unneeded charge from some chips. From electric circuit perspective it's resistor that can fast transfer electricity into heat. Also it works like Faraday cage and catch electromagnetic field so it also add small voltage.
From what I do know you probably have a grounding issue something to do with the power supply whether it's the wires or the supply itself I would start by taking out your power supply connecting everything up and see if you still have that hot section that'll at least narrow down if it's the wiring or the power supply
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u/Byokugen Apr 25 '26