whodunnit: motherboard dead

Hey folks,

My new motherboard died after only a couple of weeks on duty. The vendor says he owes me nothing, the motherborad was ok, it died of a power surge.

Let's see:

- the wall outlet for my PC is properly grounded

- the monitor on the same outlet was not affected

- a serial modem on the same outlet was not affected

- the power supply unit in the PC was not affected

- a SW receiver on the same outlet was not affected

Is it still possible that some power disturbance killed the motherboard (and the motherboard only) and how?

Thanks.

john

Reply to
hrdo
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Extremely unlikely. Most power surges damage the power supply, not the mother board, unless they come in through some peripheral device.

--
John Popelish
Reply to
John Popelish

I gather this is a FrankenPuter (Homebuilt)? How do you know it's the MB and not the RAM or CPU? If you installed the CPU yourself, it's quite likely a heat problem. If the unit was prebuilt, your vendor needs to get stuffed.

Reply to
Bill Stock

Reply to
Jim Douglas

The power disturbances include static electricity when you assembled it weeks ago, transients that enter into mother board from safety ground, and a power supply this is missing essential safety functions (very common with power supplies sold on price and without numerical specifications).

Without specific facts, such as which component on motherboard that is damaged, then no one can answer your question.

Power surges are rare events that occur typically once every eight years. Four adjacent devices can all be confronted by same transient. But if only one device provides both an incoming and outgoing path for that transient, then only that device destructively conducts the transient.

Furthermore since so many don't even know if a power surge existed, what is it, and how it damages electronics, then the power surge is that classic salesman excuse. Did a power surge ever occur? How would you know? How would the salesman know? Power surges (like heat) are the poor excuse on which blame is cast. After all, who is going to prove that accusation wrong in a world where most don't have electrical knowledge.

Far more likely, especially this time of year, is damage from static electricity.

And then so many other usual suspects exist including other defective components, motherboard conductive standoff breaking through solder mask and now touching a printed circuit trace, and infant mortality.

Without facts, no > Hey folks,

Reply to
w_tom

You should get a good UPS with filtering and spike protection. Much safer than a wall outlet. Static (6000v) could fry something especially now with so many USB external components. It could have just failed on it's own also.

Reply to
Rodney Kelp

I'll follow up on your hint that the power supply unit may be a cheap one lacking essential features. [Any models recommended?]

Otherwise, I think I was careful with static electricity and in any event its effect would not have taken a 4 week delay. Also the processor survived.

The problem was at first a wobbly boot: the machine would start and stop within a few seconds, fans still turning. To complete the boot, I pushed reset. Then one day nothing, just the peace of death.

Regards

john

Reply to
hrdo

You are correct that static electricity probably is not reason for failure. But static electricity creates overstress. Overstress results in parts slowly getting worse days or months later. Yes, static electricity does remain a possibility. Just not a more likely reason for failure.

More likely is infant mortality. IEEE Spectrum in a recent issue featured a cover story on why the human body fails. Charts there demonstrate how infant mortality causes so many failures in so short a period - and a general trend on when failures happen.

Now for another lesser reason for failure. Does the power supply manufacturer provide a long list of numerical specs. How to suspect the worst (in any technical product). The manufacturer so fears you might learn facts as to deny you those facts. In reality, maybe one percent of consumers understands specs. But without numerical specs in the hands of all, then the one percent is disempowered. IOW no long list of numerical specs - then suspect a scam. The one percent cannot sound the alarm.

An abridged list of specs that any responsible power supply manufacturer provides. If no numbers, then assume they are hiding something - missing essential functions: Specification compliance: ATX 2.03 & ATX12V v1.1 Acoustics noise 25.8dBA typical at 70w, 30cm Short circuit protection on all outputs Over voltage protection Over power protection 100% hi-pot test 100% burn in, high temperature cycled on/off PFC harmonics compliance: EN61000-3-2 + A1 + A2 EMI/RFI compliance: CE, CISPR22 & FCC part 15 class B Safety compliance: VDE, TUV, D, N, S, Fi, UL, C-UL & CB Hold up time, full load: 16ms. typical Efficiency; 100-120VAC and full range: >65% Dielectric withstand, input to frame/ground: 1800VAC, 1sec. Dielectric withstand, input to output: 1800VAC, 1sec. Ripple/noise: 1% MTBF, full load @ 25°C amb.: >100k hrs

How top dump power supplies into N America at higher profit? Forget to include essential functions. Then sell the power supply at $25 or $40 retail. A minimally acceptable power supply has a full retail price of $65. Just another number that should create suspicion.

Concept does not stop with power supplies. Concept even works for cars. Pontiac is hyping performance. So why do they not provide both horsepower and liters on the sticker sheet? Because Pontiac engines remain some of the lowest performance in the industry. Even the greater noise suggests their low performance. Just another example why the manufacturer would hide the numbers. Do the horsepower per liter arithmetic yourself. Numerical facts that the manufacturer hopes you will not learn.

Your computer symptoms only say, "Time to collect facts". In your case, I would start with a 'usual' suspect - the power supply 'system'. Not just the power supply. System includes controller on motherboard. To understand the 'system', you need a tool as essential as a screwdriver - a 3.5 digit multimeter. Concepts to better understand why boot fails are delineated in: "Computer doesnt start at all" in alt.comp.hardware on 10 Jan 2004 at

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"I think my power supply is dead" in alt.comp.hardware on 5 Feb 2004 at
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.

Another poster here demonstrates how myths are promoted. He recommends a UPS to stop spikes and surges. Even the manufacturer does not make that claim. Will the relay inside a UPS that takes tens or milliseconds to respond stop a destructive spike that is completed in microseconds? Again, how numbers expose a myth - such as a plug-in UPS for hardware protection.

Everything needs a number, or at least a numerical relationship. Without numbers, then only speculation remains. Your motherboard supplier demonstrated classic speculation. Typically destructive power surge occurs about once every eight years - another number that varies regionally and locally. Many who don't know anything about electricity hype myths such as daily surges. They just 'feel' these surges must exist. If daily surges exist, then we were trooping to the hardware store everyday to replace destroyed electronics - even 30 years ago.

Notice the need for numerical > I'll follow up on your hint that the power supply

Reply to
w_tom

Sounds like it might be a bad PS. I had one flake out slowly, where the system kept freezing up.

If it's an AMD CPU, you can check their website for recommended power supplies. Intel may have similar info.

See if your dealer will let you 'borrow' a power supply to test your theory or better still get him to do it for you. I've had several bad boards when putting together systems, several from one vendor. (Stopped dealing with them). Others vendors make you jump through the return hoops and will eventually send you a refurb months later. The latest vendor tests the dead board on the spot and hands you a new one. But I've only ever had ONE dead board from them. Some vendors resell dead boards hoping to get rid of their problems.

Reply to
Bill Stock

I would be asking the dealer how he could determine the 'surge' ocurred and perhaps show you the damaged components.

-- Regards ..... Rheilly Phoull

Reply to
Rheilly Phoull

Borrowing or swapping power supplies takes longer, puts the system at greater risk, and my only mask the original problem. The faster and cheaper procedure to first identify the problem - and one always wants to identify the problem before changing any parts - was posted previously in at:

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and
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Problem sounds like a bad power supply. It also sounds like a bad power supply controller. It also sounds like a bad power switch. It also sounds like bad motherboard capacitors....

First get facts before speculatively replac> Sounds like it might be a bad PS. I had one flake out slowly, where the

Reply to
w_tom

Thanks a lot, Tom, but you are ways above me.

Even if (big if) I manage to do all those measurements you insist on, what would be the practical consequence? Discard motherboard and PSU until you get products with good test values. Sorry, I'm not even trying. I bet you don't do it yourself.

My PSU was indeed cheap chinese junk. So dirty power and junky PSU may give an explanation of what happened, some building up of damages over time.

I'll get a good PSU for my new motherboard and I'll get an UPS, although you seem sceptical in this respect. Surely better than nothing?

Regards

john

Reply to
hrdo

Those voltage measurements may be performed by junior high school science students. There is nothing complex, difficult, or expensive in what was posted. In fact, measurements can be accomplished in just minutes. Far longer to read and learn what must be done. IOW the knowledge is that powerful and useful. As another once said, "the only thing you have to fear is fear itself". Get the meter. A tool as essential to computer work as a screw driver. So ubiquitous as to be sold even in Home Depot, Lowes, Sears, and Radio Shack.

In the meantime, a UPS is for data protection. Hardware protection that works at the appliance is already inside the appliance - as required by industry standards. Protection that may be overwhelmed IF destructive transients are not earthed before entering the building. The UPS costs what - maybe $100 - and to only protect one appliance? Ineffective hardware protection as made obvious even in manufacturer's own numerical specs. The UPS is only for data protection and not for hardware protection.

Effective hardware protecti> Thanks a lot, Tom, but you are ways above me.

Reply to
w_tom

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