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Discussion: Rare problem, PC runs on case A but not B

A

azdesign

Joined
Nov 27, 2013
Messages
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Worth to mention:
I live in a very old building that does not have any kind of electrical grounding. Everytime I touch metal part of a connected electronic device, mostly my computer, it shocks me. The shock is not hurting, instead, irritating. I sit on carpet while disassembling my stuffs.

Story:
Suddenly my PC wont turn on anymore, lets call it PC_1. So I start removing part by part, from memory, vga, hardisk, cpu, down until only motherboard and psu connected. Still won't turn on. Curious, I took another computer, lets called it PC_2. Removed everything but the motherboard and its psu. Now, I start putting in cpu, memory, vga, hardisk from PC_1 to PC_2 one by one, turns out, they are all works without any problem.

Again, curious, I put away everything from PC_2. So now there are only 2 cases, and 1 set of hardware.

Result:
Assembled everything in PC_1 case: wont turn on, no led, no beep, no nothing
Assembled everything in PC_2 case: works, no problem

Both cases shocks me when I touch any metal parts of it. Small shock, barely noticable; in some places though, strong enough it stings a bit.
The only differences between each cases is the motherboard standoff. PC_1 case have built-in standoff (welded together along the case), while PC_2 have standard removable standoff.

Question:
1. Relating this to my grounding condition, how is this happen?
2. How come it works before?
3. Someone have similar experience?
4. Is there anything like DIY grounding tricks without major electrical work with that copper rod and such.

Thank you :)
 
are you switching the power supplies too? are you sure its not just the power button? tested via shorting the pins on the mobo?
 
Yep, did that. I also confirm buttons works fine on both cases. Both power supply works in PC_2, do nothing in PC_1.
I going to try assembling PC_1 again and take it to my friend's house. See if it turns on or not.
 
Im not sure what the hell is going on but you shouldnt need any extra grounding since your all good once the power supply is connected to the motherboard and plugged into the wall. Strange that the case with built in stand-offs is the one not working because yeah they are welded.
Is it that 1 mobo is working and 1 is not?
 
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@xfia
There is nothing wrong with any hardware on both computer, including the PSU and motherboard. It just magically doesn't work when you assemblied it in case with built-in standoff

Is it normal to get shocked whenever I touch any metal parts of any power-connected peripherals?
Because it shouldn't be, if the power outlet has proper grounding. In my office, I can touch any metal parts insides my PC while it turned on without getting shocked.
Days ago, my friend brings his macbook to my place, plug the charger, and it shocks him just by touching his mac.
Grounding a whole building requires hiring technician and quite costly.
 
i'm going to say the grounding issues are causing the problem, since one case must be earthing differently to the other.

other than using earthed outlets, you probably cant do anything about it.
 
Indonesia.
Changing outlets works.. I bring my PC_1 to kitchen, tried plugging into kitchen outlet, turn on, works...
I just don't know whats going on anymore, my kitchen should be same ungrounded as well.
So yeah, going to call technician to ground every single outlets
 
azdesign said:
Indonesia.
Changing outlets works.. I bring my PC_1 to kitchen, tried plugging into kitchen outlet, turn on, works...
I just don't know whats going on anymore, my kitchen should be same ungrounded as well.
So yeah, going to call technician to ground every single outlets
Click to expand...
do you get shocked when you touch metal parts of your stove or pc when it is plugged in kitchen
 
hmmm
how long do you live in this house. did you bought it resently or it is long house. how long is since you have this problem.
what kind of plugs do you have in your house schuko or something else.
 
Your problem is your house socket does not seem to have an Earth point to ground electronics with exposed metal parts. The solution is to have earth points on all sockets. It is not expensive fix if you have basic wiring skills.

By the way how you power socket look like? Is is just two points only or two pin plugs? If so that is the cause of grounding problems. For a socket to have grounding it needs one more pin called the earth. This is use to ground any excess electricity that leaked to a metal. For two pins plug electronics use what is called double insulation to prevent shocks.
 
Been here for about 7 years. Had different kind of PC until now but this case with built-in standoff is my first since 3 months ago. Never had any problem before with failures caused by static.
Yep schuko 2 prongs plugs. I did more test again just now, plug into different kind of outlets. Bathroom, garage, bedroom. 3 places, 2 works, 1 doesn't. So random

--edit

I don't have electrical knowledge, gonna call technician later.
Should I change all outlets into 3 pin?
 
what kind are the sockets you've tried
like this
180px-Stopcontact.jpg


or like this
320px-Schuko_LH_without_shutters_RH_with.jpg
 
azdesign said:
the 2nd one, with metal on sides
Click to expand...

The metal on the sides of the sockets is the Earth point. Now we know that you are off to a good start as there is less electrical work to do. Now what is left to know it the plug. Does you plug of your PC have metal points at the side?
 
yes, plug also have metal on sides.

-- edit

opens up one of the plug, cable consists of 2 wire, no wire for ground. The plug accept 3 points
 
azdesign said:
yes, plug also have metal on sides.

-- edit

opens up one of the plug, cable consists of 2 wire, no wire for ground. The plug accept 3 points
Click to expand...

Yeah was gonna say that doesn't mean it's grounded. You might not have ground anywhere.
 
well since you have the grounded outlets when your home was built they either got lazy and didnt ground anything or a wiesel ate through the wire
 
I remember when I replaced one of the outlets long time ago, there were only 2 wires inside the pipe on the wall, the 3rd, ground wire is missing thus not connected to the outlet
 
I use to live in a place that didnt have grounded outlets so I moved eventually.. I mean if you rent then dont pay to fix a house that is not yours.
I was able to make my pc work fine with a nice power strip.
Never got shocked liked you but I could make the pc hang just by touching it for a second.
 
Can you try using a plug with all 3 points wired up? Yes that would mean that grounding is not in use when it is not wired up. Grounding point should be standard in many houses today as it is a very big safety feature in the case of an electrical failure to prevent electrical shocks. Definetly get a an electrician to look at it.

Just a sidenote, the case without the welded standoff works because it is more insulated than the case with the welded stand off. Technically you can make you PC "double insulated" by taping electrical tape on any exposed metal parts like the standoff and the PSU so it would not end up shocking the case. Even so I do not recommend doing that as the PC is not design from the ground up to be like that with this "floating ground" design. It not very safe.
 
@xfia
pc hang after touching it? hmm, never knew it possible

@MIRTAZAPINE
Thanks I will soon find eletrician to work in my house. Is putting a UPS between outlet and my PC will have some kind of grounding? Aren't they run on DC?
 
Yeah it would like flicker and crash too but not at a friends with a brand new house.
You dont actually get grounded if a UPS is not grounded at the wall..
Guess I could say it stabilized things a bit for me or something.
I just mentioned it because old houses can just be that old so the electrician comes to do his thing and then he says something about the foundation, pipes etc.. and 3 building maintenance companies in your realizing you could put a down payment on a modern house or apartment.
 
aha so problem is that gorunding isnt connected at all.
you can fix it by yourself it isnt hard but you have to be careful and to turn off power before you start workng.
here is guide how to wire schuko plug http://www.howtospecialist.com/installation/electrical/how-to-wire-and-install-an-electric-output/
but most likely wireing in your house dont have grounding cable (green/yellow one) or you wouldnt have problems you have.
in order to fix this you need mains tester like this
033%20HCO%20031.jpg
, screw driver and some spare wire (0.75-1mm2).
check where is live wire with tester and on socket cover put dot with marker over hole of life wire. turn off power and remove cover. transfer marker dot to the base of the socket (the part that is in the wall) and take out socket base from the wall.
cut ~5cm from spare wire and strip about 1cm insulation from both sides.
wire grounding pin to the nul cable (the one W/O marker dot). if wireing in you house is made properly all life wires should be same coler but still check em with tester for just in case.
tighten bolts of the wires and check with 2 fingers and mid force if you can pull out cables out of their places. if cable popped out reseat it and tighten bolts again.
reseat socket in the wall place cover back turn on power and test all pins with mains tester (grounding pin too). if tester lights on anything beside marked pin you've made a mistake with wireing.
if everything is ok you can test socket with real device. plug it into socket and check if you are shocked from metal parts.
repeat for all sockets in your house.
 
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