PCs are a lot more hardy than you would think. They convert the AC to DC and
back to AC so most line noise is lost in the translation. The "line filter" is
there to keep the trash from the PC supply, out of your TV and radio.
That said, if your lights aren't flickering, and your TV flashing snow, your
power is probably OK.
If your lights are flickering there is the probability of a loose connection
in your wiring somewhere. It is also possible that there is a loose neutral
connection somewhere and one side of the line is getting a higher voltage
and the other side is getting a reduced voltage. This would be evident if
some lights in the house get brighter for a moment while others get dimmer.
This could cause a higher voltage to your computer for a moment if the
computer is plugged into that circuit and may just overload the power supply
for just long enough to make it crash.
You should get this fixed right away.
I have seen computers go unstable because the homeowner
removed all safety ground wires in the breaker box. Once
demonstrated to him, then he would blame me for his problems.
Never did discover why that missing safety ground caused his
intermittent failures. Normally missing safety ground should
not because computers should be that robust.
But missing safety grounds can cause peripheral failure.
This was a serious problem with HP LaserJet II printers. When
some put mechanical switch boxes between printer and computer,
then the switch box would disconnect ground. This caused
LaserJet damage. A problem that would not have occurred if
computer and peripheral both shared a common safety ground.
Lights flickering would be from something else such as wall
receptacles connected using wires stabbed into receptacle rear
rather than properly wrapped around screws or maybe a loose
wire in breaker box. Flickering lights from a voltage drop
more than 15 milliseconds long may cause a computer to reset.
The safety ground in a wall receptacle does nothing to make
a surge protector effective. Many don't understand the
different concepts of grounding. Surge protectors need earth
ground - not safety ground. Missing earth ground is why a
plug-in protector can even contribute to damage of an adjacent
and powered off computer. To be effective, the protector must
be connect to AC mains and less than 10 foot from earth ground
- not safety ground. Ineffective and grossly overpriced
protector just forget to mention that part.
But surge protector has nothing to do with intermittent
computer problems. Surges are rare events - typically once
every eight years. Is your problem more frequent?
Strange, my PC is also a HP. I've been told the power supply that they use
isn't the best. But like I said I replaced the power supply and it still
shut down on me. The first HD ended up with bad sectors from all the outages
that I had, so I bought a new HD and whenever it shut down on me also. I
reinstalled the old HD just until I get the problem figured out. Surely
don't want the new hard drive ending up like that.
I do have a Decor-Surge 3 stage made by Snapit. It enables me to have 6
plugs instead of just the normal 2. Do you think this could be the problem?
We live in Louisiana and do have severe weather that causes frequent
electrical problems also.
First if supply was in a brand name computer, then it was
typically superior to what is found in most clone built
machines. If you replaced the supply with something typically
sold for less than $60 retail, then you probably installed an
inferior supply. Furthermore, if someone recommended
replacing a power supply without first taking numerical
measurements, then suspect the worst. On this I must be blunt
because so many computer repairs are recommended by junk
scientists - people who cannot be bothered to first learn the
meaning and power of numbers. A power supply need not be
replaced when the numbers and manufacturer specifications say
it was perfectly good.
Second, to further answer your questions, basic information
must be provided. For example, what is the operating system
and what is the disk filesystem? What peripherals are
attached and how are those peripherals powered? Intel or AMD
The Decor-Surge 3 stage protector would typically do same as
every other plug-in power strip and UPS protector. It has no
effect on your problem since it remains inert - does nothing -
acts like it was not even connected unless a 300+ volt surge
occurs. An event that occurs typically once every eight
years. An event made obvious by other damaged electronics.
Its an HP. So download their comprehensive diagnostics for
your hardware. What did diagnostics report? If using XP or
any other NT based OS, then what is the important information
in the system (event) log. What did Device manager report?
Of course you have done the obvious - run a currently updated
virus checker on the system.
And again, why is the AC circuit dimming out. Again, if
loss of power is something more than 0.015 seconds, then the
power supply must reset the computer. So why is that power
flicking out periodically? This is sometimes directly
traceable to bad household wiring, as described earlier, that
is perfectly acceptable for electric lights and other simpler
appliances. Describes previously is how to not wire a house
(as too many electricians still do) because intelligent
appliances now exist.
As for severe weather threat: concepts involve the essential
earth ground with every incoming utility connected to that
single point earth ground. A connection either via hardwire,
or via a 'whole house' protector. The protector only
effective; making a connection to earth ground during the rare
extreme transient. Again, that plug-in protector does nothing
for your current problem nor does it even claim to protect
from surges typically created by severe storms. Plug-in
protectors (that are also grossly overpriced) are recommended
only by those who don't even understand what protectors do.
To solve your problem, first we must know why problem exists
before even consider fixing it. Answers to above questions
Hi, can't say how much I appreciate your help.
I have a HP Pavilion 531w, purchased July 2002, Windows XP Home Edition,
NTFS. HP DeskJet 3820 printer, HP PS2 Keyboard (2K-3), PS/2 compatible
mouse, Sony CD-Writer (internal). Intel Celeron CPU 1.30 GHz. (The Sony
CD-Writer was a replacement for the original CD-writer.)
I have the Norton's Anti-virus program and I keep it up to date.
I'm not sure what the problem is, with the house lights flickering.But like
I mentioned before, this is an old house (over 55 years), also, it was built
out of 2 old houses at that time. Just hope they didn't use the same wiring
from the original 2 houses.
I will see what kind of diagnostic tests I can find and run and please let
me know if you need any further information. I will let you know what I find
out with the tests, K?
Thanks so much, Donna J.
Its an NT based OS. Therefore the system (Event) logs are a
major source of information. If you don't know where the
event logs are, then use Windows Help to locate and read
them. If they make no sense, then post the recent information
from that log.
Also what sometimes provides information is the Device
Manager. Locate and identify any devices the system has
marked with a yellow encased exclamation point - indicating
hardware or driver failure.
Hi, I took the new hard drive out and have the original one back in. Just
didn't want to take any chances with messing my new hard drive up. I've not
had any shutdowns since I reinstalled the hard drive with the bad sectors. I
checked the Device Manager and there are no problems there. I will change
the hard drive out again and look at the system (event) logs and device
manager to see what I can find.
You also mentioned flickering lights. There is a circuit on
motherboard to control power supply. If power line voltage
rises and falls too often too fast, then this circuit locks
out. It is hardware protection that can only be reset by
removing power cord from wall. Is that (type of surge) where
your problem lies? Symptoms are correct. This type of surge
could be creates by an intermittent arcing wire inside walls.
Also typical of a surge that no surge protector would ever see
because it is not a voltage transient.
Furthermore, could not safety ground make this circuit trip
into safety cutoff? Maybe, but we don't have circuit details
to say for sure.
Just another reason to first start with the dimming light
phenomena that should not be happening. Your flickering is
not just dimming? It is really flickering? Lights blinking
off every for tenths of seconds is more than a nuisance. It
may be a human safety threat. And it could trip that
motherboard safety circuit.
One indication of internal and intermittent wire problems is
how severe is the dimming. Placing a heavy load at the end
of that circuit may tend to aggravate the problem. With a
heavy load, then voltage at end of that wire would be
significantly lower (which means of course you have the
necessary too - 3.5 digit multimeter).
Heavy load (ie electric heater) at end of circuit would also
cause a noticeable dimming of incandescent lamps that share
same circuit - if wire in wall is a problem. Dimming of
lights means something is wrong or weakened.
Electrician could discover why problem exists. But more
important is to first make the problem reproducible - so that
you have something to show the electrician. Better you do the
easy labor rather than have him do it at electrician rates.
Take inventory of what is on, what is off, and what changes
(on to off, or off to on) when dimming occurs.
Seriously consider having a new circuit run to that computer
so that computer has a safety ground, as computer was designed
to need. Safety ground (or GFCI) should also be in kitchen
and bathrooms. Additionally, electrician could install the
upgraded (required since 1990) earth ground and a 'whole
house' protector. Minimally acceptable protector can be
obtained at Home Depot for less than $50. Some electricians
instead install an undersized Square D protector that costs
much more money.
IOW give him enough that he can create and therefore find
reason for dimming. Then also take advantage of his arrival
by having other basic stuff fixed. Even if kitchen grounded
outlets are too expensive, still, get that earthing ground and
'whole house' protector installed. Much cheaper to have done
when you have already paid for his traveling time on this
Hi, I've never had any problem with the lights dimming in this room. In
the kitchen, the light over the table flickers occassionally, also sometimes
when I use the microwave it will make the light over the sink flicker. I
will have this outlet checked to make sure it is working correctly, then
will let the newsgroup know if I still have problems. My PC doesn't shut
down everyday, I never know when to expect it. So it may take a few days
before it happens again.
Is it possible to add a new circuit with a ground just in one room of the
house? if there is a problem with this outlet?
We have a new Home Depot close by, so I will check and see if they have
the protector you mentioned.
Thanks again, I appreciate the help.
Yes, but ground is not your problem. PC's do not need ground to operate
properly. PC's are grounded for safety. Consider a laptop - the line cord
is two wires with no ground prong - it has no ground connection, yet
all the same functions as a "regular" PC.
A surge protector won't address your problem, either.
Address the flickering problem first. If you still have a problem
with the PC dropping power after the flickering problem is resolved
I have seen where a computer would not work only when
plugged into a house where someone had cut off all safety
ground wires in the breaker box. If computer comes with a
safety ground wire, then computer is designed on the
assumption that safety ground will exist. If that safety
ground wire is not connected, then stray 60+ voltage might
exist - which causes other problem and failures when computer
is connected to peripherals.
Some computers have worked just fine without that safety
ground. I have seen another fail due to no safety ground. We
know (even from the HP Laserjet II experience) that missing
safety grounds can cause hardware failure.
Will safety ground fix the problem? Maybe yes; maybe no.
Just because a laptop designed only to work on two wires
exists does not mean that a computer designed for three prongs
will not fail on two prong power. Those two computers (the
three prong verses two prong) are designed differently.
A surge protector is not to fix the problem. The surge
protector recommendation was because an electrician was
already paid to appear, will already be working inside the
breaker box, and should also be utilized to upgrade earth
ground and install 'whole house' protector. Recommendation
made to maximize value of an electrician for long term benefit
to computer and other electronics.
Tom - for lord's sake - he's got flickering lights. In addition, his PC
How on earth can a missing ground casue either one of those problems?
Which problem presents greater risk to him?
Your presentation contains no facts, and invalid assumptions. Saying
a "stray 60+ voltage might exist" is a non-specific, unsupported
speculation. It does not state where the voltage is, why the figure
is 60+, where it came from, and whether it is a "bad thing", a
"good thing", or an interesting but irrelevant item. Aside from
the power supply, the electronics is NOT designed with a three prong
plug in mind. That third wire is there for safety. The NEC does
not allow you to consider the grounding wires as a current carrying
conductor (article 400-5 1999 NEC) - a manufacturer must not
intentionally introduce any current to that grounding conductor.
Does he have flickering lights or just dimming lights?
Until he answers the question that was posted previously, then
do you really know?
In the meantime, 60 Hz AC leakage voltages can cause
problems with the power supply controller on motherboard on
some computers. I have seen it as previously posted. If you
don't why it can happen, well then you were not a digital
logic designer (IOW where does that leaking 60+ AC go?).
Instead of invoking the lord, look at the original post. He
asked if missing safety ground can cause computer problems.
The answer is yes. In addition to addressing the flickering
light problem (which was already done and apparently does not
occur when computer has problems), he also has a potential
problem that is described as quoted:
Yes, a missing safety ground, in some cases, can also create
this problem AND cause hardware damage. Will you focus
blindly on the flickering lights and ignore all other
potential reasons for that computer problem? The flickering
lights possibility has already been addressed and is awaiting
further information from the OP. No reason for you to now
bring the Lord's Sakes into this discussion.
Yes that third wire is for safety. But some designs use it
to carry away the 60 hz leakage. You have never seen an Intel
USART destroyed because that leakage (120 microamp) 60+ volts
found another path when safety ground was missing? USART
damaged, in part, because safety ground was missing -
irregardless of the lord's sake.
He said flickering. Whether you wish to quibble on flickering vs dimming,
he's got a symptom that could be a disaster in the making, and is a probable
cause of his PC problem. It is the first thing to address.
Again, a non-specific reference to leakage voltages. Specify the leakage:
where is it and what causes it? For example, lets say you have 60+ volts
on the PC chassis with respect to ground, due to a leaky capacitor.
The correct fix is to replace the capacitor. You need to specify what you
are thinking of when you talk about "60 Hz leakage voltage"
You may have seen it, but you have not identified the source of
the leakage, nor stated where the voltage existed. Where did
you connect your meter leads? How did you determine it
was "leakage" voltage and what do you mean by "leakage"?
How did you determine it was 60 Hz?
If some component is leaking such that it creates a condition
where 60+ volts (with respect to some point you have not yet
identified) exists where it shouldn't, then isn't replacing the defective
component the correct fix? (I mention 60+ volts, as that is the figure
you used in a previous post. ) If the chassis of a PC is at 60+
volts (or some other objectionable voltage) with respect to ground
due to a leaking capacitor, and that is causing the PC to drop power,
installing an equipment grounding conductor very well might make
the PC stop dropping power. You haven't resolved the problem,
you've only hidden it. The correct thing to do is determine the
source of the problem and fix whatever is causing it.
Because you are unable/unwilling to specify what you are talking about,
you deremine that someone else is not a digital logic designer (or a piano
tuner or a farmer or whatever)??? That makes no sense.
The answer is NO, with no equivocation. You need some condition
other than a missing equipment grounding conductor, to cause a PC to
drop power when it should not. The NEC prohibits using the egc as
a current carrying conductor. Perhaps you don't understand the
distinction, since it is NEC terminology. It means that manufacturer
and designers cannot intentionally design or build a PC that requires
the egc to carry current under normal conditions. It is for safety only.
Look, this should be simple. You claim that some PC's need the
egc to avoid the symptom that the OP asked about - dropping
power. You say designers use the egc to prevent that. What are
the specifics you have in mind? How do the designers use the egc
to accomplish this? What is the circuit?
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