Nice Lesson in Computer Repair

[Gator01]

Originally posted by TEShaw
I'm an $700 idiot.

Hell in computers alone I'm at lest a four figure idiot... add the car in there and you can add even more digits.

Live and learn.

Let me know if you do get that computer running on the curcuit that was built for it, I’m curious.

[TEShaw]

No, here's the deal: there is recently something wrong with that household circuit...

nothing else on there but the computers...but it has to be bad...

the computers work from every other circuit in the house...

OK, I lied; I'm not a big-shot electrician, I only wired this entire house, and for 8 years this computer circuit has been solid...

can there be possibly be something bad now about the circuit-breaker that makes this one dedicated circuit bad?

Sheesh, I just wasted $700 dollars to fake computer repair guys (hint to guys who have no jobs yet.)

[TEShaw]

Gator, the computers  work fine from extension cords from outside the house.

Plus the jerks at the computer shop screwd me.

Plus, what can I do? Put a new 15 amp breaker in the scarey outside box?

(Yeah, I know, go to the outside box, shut off all incoming power, I can do it! )

Guess, I'll have to be an electrical hero.

OK, I don't even remember what this circuit breaker I previously installed even does, but it had to be at least 15 amps; why is this dumb dedicated circuit f***ing me around?

I'll remind you that these computers are supposed to be on a single dedicated circuit that I designed and the f*****g electricians okayed..

Plus this circuit has worked fine for the last 2 years.

I don't get it.

Buy and install new circuit breaker in the big, scarey, electrical box outside my house? I can do it!

I'm trying to be nice here.

[NHawk]

Shaw, I'm not sure where you are but there is one fact that holds true wherever ac power and circuit breakers are involved. You either have power or you don't. There's no in between that would let one system run and the other not (other than a bad outlet or loose connection).

If the breaker isn't tripped, I'd be looking at the outlets in the room for loose connections or just plain bad outlets. If it is tripped, you could have a more serious problem or as you say, you may just have a bad breaker.

Edit: If you're where I think you are (down under), that new power supply you got may have a mainland China power cord that looks identical to your cords, but doesn't fit properly in the recessed outlets you use. That would also explain why the extension cord works, but the outlet doesn't. The easy way to test that is to take the cord off of the computer that works and put it on the one that doesn't.

The reason there's a long span between the post and edit time is I was an electrical engineer for most of my life and retired from it 7 years ago. I knew there was something different down under but couldn't put my finger on it. So, I called a friend who is still in the industry and he simply said the outlets are different. That sparked my memory, and posted about the recessed outlet and it also brings to mind that the hot (you call it active I think) and neutral are reversed on China cords as compared to Aussie cords.

[Skuzzy]

There is only a couple of things that could effect a local circuit in a home.

1)  The gauge of wire.  If the gauge is too small, the wire will not be able to carry the current needed to power the larger computer.  The breaker need not trip in **** case, but the wire will getvery warm and could represent a fire hazard.

2)  The wiring run is of sufficient length that the voltage levels are dropping below what the switching power supply in the computer needs to function.  Again this points to too small a gauge of wire being used.

3)  Improper ground in the AC circuit.  Iti s posiible the ground in that circuit is an electrical gounrd versus an Earth ground?  A simple ground test should show something wrong if this is the case.

If I reacll, you said this is an 8 year old circuit.  POssibly the combination of age and smaller gauge wiring?  As copper ages, its resistance does increase slightly.

Also, I assume you have switched out the power strip and tried another one.  Not just a different socket.  A different strip.


Just some thoughts.

[Irwink!]

Originally posted by TEShaw
For whatever you blah lah type...

there is one thing for certain:

My computer fails to start on the one circuit...

But it starts fine on the other circuit.

Draw your own conclusions.

 
 I have. You have ventured into a field for which you have just enough knowledge to kill yourself and/or others. Do-it-yourself "electricians" are truly scary. Call a real electrician.

Gator01: Power factor in a single phase residential circuit!? Amazing...

[AKDogg]

Originally posted by Skuzzy
[3)  Improper ground in the AC circuit.  Iti s posiible the ground in that circuit is an electrical gounrd versus an Earth ground?  A simple ground test should show something wrong if this is the case.
[/B]

This is what I was gonna say.  Check the ground in that circuit.  I willing to bet its bad.  Circuits can go bad because of those pesky field mice too,lol.

[Gator01]

Originally posted by Irwink!
Gator01: Power factor in a single phase residential circuit!? Amazing...

I didn’t say it was a common occurrence, but it is a possibility that hasn’t been rolled out yet.  Another possibility is divine intervention, but I think that isn’t likely...  The big man has got bigger things on his plate, and it doesn’t seem like Shaw has done anything to warrant his wrath.

In order for one power supply to work and the other not, there has to be a difference between them.  All I can think of as even possibilities are sensitivity to noise, PF, and as Skuzzy said improper grounding.  The last of which now that I think about it seems like a more “common sense” diagnosis and the simplest solution is normally the correct one.

As for wire size and lenght, I'm not saying that couldn't be it, but the only way that would affect the power supply would be through a voltage drop at the outlet.  My feeling is that that both supplies would be equally sensitive to reduced voltage...  plus it sounds like he had two computer running on the curcuit for some time before, and they both worked, and the house didn't burn down.

[NHawk]

I hate to do this, but ROFL. Do you know how long the wire would need to be to have the voltage drop below 100 volts on a 120 volt/15 amp circuit? Can we say somewhere around 400ft with 14ga wire at full load? That's why voltage drop usually isn't a problem in your common home.

[Edit:] Even using 18ga wire (totally illegal everywhere) you'd be looking around 160ft for that kind of drop. And yes you would have one heck of a toaster going with that wire. [/edit]

I will agree with the possibility of under sized wire combined with being too long and the breaker not tripping. But he did say the circuit design was approved by engineers. So, I'd not be looking there unless he cheated when he wired it.

But let's also remember we're talking about a computer here. It doesn't draw a whole heck of alot of amperage. Maybe 4 to 5 amps at 120v, half that at 220v.

[airspro]

they just replaced whatever part most sounded like it would solve the temporary problem.

What makes you think they "replaced" anything as it most likely worked for them when the tryed it on their bench .

I got shafted once at a car dealership that way once , NEVER GONNA HAPPEN AGAIN .

I would be for SURE going back to that workshop and getting EVERYTHING that they took out of your PC . Or getting it out of their HIDES .

[TEShaw]

I totaly appreciate all your ideas. Please keep them coming.

And, you're obviously not required to electrify my house.

I haven't gone out to look again, but this is probably a 20 amp circuit that I installed with the appropriate Romex wiring. Plus, the electricians checked it for code. And, it has worked fine for 8 years.

The outdoor-box and direct-wired circuit are less than 15 feet from where I'm typing.

I can use the extension cord and run the computer from every other circuit in my house.


How could the newest, freshest circuit in my house go bad except for something about the circuit-breaker, which, I cannot even imagine.

Nontheless, I can run the computer from an extension cord, from any other outlet in the house.

The length of the tines on the cord not matching the outlet? This is the best suggestion you've given me so far...but all my other senses say that I shouldn't crawl around under the desk to like, SOMEHOW check this out.

I am so sick of crawling under this desk.

Plus, the computer repair guys totally jagged me for $700, which is what this thread is about.

Plus, this circuit has the same ground as everything else in the outside box, that powers everything in my stupid house. C'mon, grounding cannot be issue.

[Chilli]

Originally posted by airspro
What makes you think they "replaced" anything as it most likely worked for them when the tryed it on their bench .

I got shafted once at a car dealership that way once , NEVER GONNA HAPPEN AGAIN .

I would be for SURE going back to that workshop and getting EVERYTHING that they took out of your PC . Or getting it out of their HIDES .

E'rthing that Airspro just said, except don't take it out of their hides, I recommend presenting them a fuel bill for the 4 ... err (now 5) trips there.

 Don't feel the least bit bad about it.  In-laws just got security windows done $26K.  Then sister-in -law gets the same quote from same guy  (end result -- same job  for $11k)  and I still think they both got taken!!!!

[Solar10]

Guys, I really don't think he wants help.  He is not listening or willing to climb under the desk.  Let him use the extension cord and sulk over his $700.  In the mean time the circuit could be degrading to a point where it becomes a fire hazard.

[TequilaChaser]

Polarity?  either in the outlet or in the power supply

[TEShaw]

I am still trying to be a nice guy.

I don't know what's going on.

Solar, I'm logging on now from the dumb computer, then I'm going to shoot you down.

Be prepared.