Help, my comp is dying or dead
 

My computer is not turning on.

The case fan is turning on and the usb is getting power, however the hard dives do not spin, and the BIOS does not load.

Any idea my fellow cellar dwellers.

Ours was doing that a couple of months ago. It was a dying power supply.

How can I test my power supply with out getting a new one just yet?

Toran....where you tinkering inside the caseing?

Easiest way to is get a tool sold where screwdrivers are sold - in Kmart, Sears, Radio Shack, Lowes, etc. A $20 meter will identify a failure without doubt. If a new power supply is required, the meter is necessary to confirm that new supply as OK. Even a defective power supply can boot a computer.

A second option sometimes can report a power supply either defective or unknown. Unplug wall power. Disconnect supply from motherboard. Reconnect to wall power. Using a paper clip or wire, jumper the green wire to a black wire. If fan does not spin even an eight turn, then power supply might be defective. If fan does spin, it says nothing useful about the supply. And still other parts of the power 'system' are unknown. Digital meter is the only way to get a useful answer, to identify other 'system' components as good or bad, and is required if a new supply is purchased.

As shown here.

Power supplies can be had pretty damn cheaply anyway...

That is a power supply tester. It cannot report a good power supply. It is at best what is called Go-Nogo tester. Even in quality as taught by Deming, that would be an undesireable device. It can identify some defective power supplies - not all. Required is a device that reports good or bad with no doubts.

That tester provides no numbers. To properly load a power supply, a tester must be as hot as four light bulbs in one package - way to hot to handle. Obvously, the tester applies no such load. That power supply tester even has no other useful purposes. A power supply tester for maybe $10 will never accomplish what a $20 3.5 digit multimeter can accomplish. Most obvious difference: a useful diagnostic tool provides numbers.

Avoid the power supply tester as if it was a disease. It does only slightly more than the paper clip described earlier. Defined was a defective power supply that can still boot a computer. Power supply tester would declare that defective supply as good.

The recommended 3.5 digit meter for $20 is sold in Lowes, Radio Shack, Sears, Home Depot, Tru Value Hardware, K-mart, and Ace Hardware. Last time I looked, it sold for $16 in Walmart. The tool is that universal and has numerous other useful functions.

Power supply must cost about $60 retail. Critical functions are often missing in supplies selling for less. Last time I looked, every replacement supply selling in CompUSA did not meet minimum requirements. The power supply market is ripe with dumping because a power supply manufacturer need not meet industry standards. The computer assembler must know of and is responsible for meeting those standards at the system level. Why bother including all functions when the customer assumes all power supplies are identical? Ironically, profit margins on some cheaper supplies may even be higher. That much is sometimes missing inside a supply.

Thank you for explaining supply-side economics to us ;)

Economics discusses profits on a large scale. Why would a profit on one $40 power supply be larger than the profit of a $60 supply?

ahem, ;) ;) ;)
coughitwascoughajokecough
coughnotaverycoughfunnyonethoughcough

Seriously, if you don't know what you're doing, as in, don't have or know the right tools, I reckon you should not be playing around inside the computer. Take it to a pro and shell out a few bucks extra. You risk zapping yourself, setting up a fire hazard, or most likely, just overloading and frying some important components.
A mate of mine had a similar problem, his laptop was just not starting (OS compromised) and so had the great idea to connect the laptop hard disk to his desktop computer. Ooops. Different voltages. Sizzlesizzlezipppffftt. Imagine watching 15,000 words of your thesis - about 2 months of work - climbing to the ceiling on a thin wisp of smoke. ooohhhh dear. :(

I hope Toran responds to my question if he can.....This happened to me very recently. I had that issue and it was a very easy fix......We thought motherboard...power supply...etc. etc...and it was actually very easy to fix.

Voltages inside the car are higher and more dangerous than inside a computer. Computers are so easy that almost anyone can be a professional computer repair person. Even every connector is different or keyed so that one cannot connect wrong things together.

There are two complex rules in computer repair. Disconnect the power cord before removing or installing anything. Touch the case before touching anything else to discharge static electricity.

How complex is an Ipod? If the Ipod is too complex, then suggestions for computer analysis posted here are also too complex. An Ipod is more difficult than the meter. Yes, that is how little some 'geek squad' techs learn to become 'experts'.

Meanwhile a power supply selling for less that $60 full retail is computer failure just waiting to happen.

No,\

tw, you have posted about power supplies in the past. Can you link to a power supply that you would buy, and explain what it has that makes it different?

Too many power supply manufacturers (hundreds if not thousands) meaning too much time to assemble a list. However basic market techniques used to buy anything technical also apply to a power supply.

First, market retail price makes obvious supplies that are missing essential functions. Minimum sufficient supplies are about $60 full retail (not to be confused with discounted prices for that same model). That does not even imply a $100 supply is sufficient as one might assume using binary logic.

Second, a manufacturer provides a long list of numeric spec. A manufacturer dumping an inferior product will not provide those specs so that the 1% who actually know technology cannot 'blow the whistle'. What constitutes numeric specs for a power supply? So many numbers as to fill a page. Some of those manufacturer numbers that must exist in writing would include:
Short circuit protection on all outputs (short all outputs together and still power supply will never fail)
Over voltage protection (power supply will never damage any other computer components)
Over power protection (too many computer components never causes damage to a supply)
EMI/RFI compliance for CE, CISPR22, FCC part 15 (ie put an AM (medium wave) radio next to computer and have no interference)
Safety compliance for VDE, TUV, D, N, S, Fi, UL, C, UL, CB
Full load hold up time (how long power supply works just fine with no AC power input): 16msec.
Efficiency greater than 65% (power supplies should exceed this number although conservatively rated supplies may only list this number)
Ripple or noise 1%
MTBF under full load at 25°C >100k hrs
Acoustics noise listed in dB while under full load.

Third, only useful power supply reviews always do tests such as loading the power supply to 100% rated power and measure its voltages. Also short all power supply outputs and demonstrate no failure. Tom's Hardware was one of so few web sites that performed such tests. Most reviews are so technically pathetic as to discuss appearance, weight, and some implied convenience.

Fourth, recommendations from many computer techs often mean nothing. To be A+ Certified, a computer tech need not even know how electricity works. Too many techs will push irrelevant numbers such as total wattage and will also hype more fans.

Even better supplies are also universal. These are features beyond minimal requirements. For example, a 120 volt power supply works just fine when AC voltage is at 90 volts or rises to 265 volts - just like all laptops. Many supplies that do this will claim a minimum voltage of 100 VAC or less. Such 120 VAC supplies will often work even at 85 VAC.

Even better supplies also include power factor correction which means its AC power interface is even more robust as well as more efficient.

Some manufacturers are often listed repeatedly for their superior designs including Antec, Computer Power & Cooling, and Seasonic. That does not mean every supply from these companies are best. But as noted previously, no supply observed in CompUSA appeared to be minimally acceptable. Dumped supplies into an American market flooded with technically naive computer assemblers is so profitable.

A quickest identifier of a defective supply is the AM (medium wave) radio test. If a power supply interferes with reception, then the power supply probably has multiple severe deficiencies.

Move on to wattage. Total wattage says little useful. For example a Dell 300 watt power supply might be rated as 430 watts by a clone manufacturer. Neither watt number is a lie. But many computer assemblers would not understand why those two numbers accurately measure the same supply.

More important are output amperage for each voltage. Unfortunately, no one can accurately say what the actual load will be or if that power supply is actually performing properly. A fully assembled computer with all peripherals accessed simultaneously has output voltages measure using a multimeter. If building a computer, there is no way around confirming hardware with measured numbers. If the computer has a motherboard voltage monitor, that motherboard function also must be calibrated with the meter.

None of this is complex. Most of this takes longer to read here than to actually perform - except if a power supply manufacturer makes doing this difficult.

Wow, thanks for that informative answer.

One more question, which may sound kind of dumb after all the information you just provided, but the fan in my 2 year old Dell at home makes a fluctuating noise. When I'm doing something really CPU intensive it makes a lot of noise and when I'm just typing in a reply box in the Cellar, it makes a sort of oscillating noise. Sometimes louder, sometimes softer. The PC seems perfectly fine otherwise. This noise isn't a screech like bearings failing, it's maybe just the fan speeding up or slowing down. Is that in itself a signal that the power supply may be failing? If it's failing, I'm going to be glad that you posted what you just did, so I can get a decent replacement.

P.S. I have a multimeter that I use for household electrical work, but have never used on electronics.

That's probably not a problem. In the past few years some manufacturers leave the fans low when they're not as necessary, so the PCs stay quieter.

As UT notes, a power supply may change fan speeds based upon temperature. These design variations are numerous. Early versions has a thermistor inside the fan alongside a transistor and hall effect sensor. Yes, electronics are even inside each fan.

A computer assembler really cannot duplicate this. That power supply fan must move enough air to also keep the case cool in a 100 degree room. IOW that fan control must be integrated with other electronics on motherboard. Dell can integrate that fan control. Same may be too complex for a computer assembler for a clone machine.

Easier is to integrate under motherboard control a fan that often makes creates noise - CPU heatsink fan.

CPU temperatures can vary drastically. To appreciate how much, view why that power supply is located on motherboard adjacent to the CPU. A CPU may go from drawing less than one amp to tens of amps. To make a CPU even hotter, that current demand may occur in microseconds. Therefore a CPU fan may power cycle because CPU power consumption can vary greatly.

Another sidebar - why do fans fail? Many will blame only what they can detect - a sticky or worn bearing, or excessive dust. Fans are designed with sufficient torque to overwhelm such restrictions. However, if fan electronics sensor gets misaligned, then actual fan torque can be signficantly reduced. Some fans may not startup everytime or may eventually start moving later. One such fan over a generation ago resulted in three separate service calls involving a long airplane trip before a mysterious failure was finally traced to a 'sometimes sticky' fan.

I'm not going to worry about it then, since there are no other symptoms. Thanks, both of you.

Ok, I have been doing some playing, I haven't raised the funds to get a tester just yet. However on closer inspection I have notices that my cpu fan is not spinning and my hard drives are spinning.

Don't run it in that condition. The CPU fan is necessary.

It can be a power supply, but I've had dust cake onto a CPU fan and stop it when it got a little damp. The dust turned to paste.

It can also be that the CPU fan has become unplugged from the mainboard fan header. Look for the two wires coming off the fan, and make sure they're plugged in somewhere.

The tester is useless. Get a 3.5 digit multimeter - a completely different item - as sold in Sears, Radio Shack, Tru-Value Hardware, K-mart, Lowes ... A tool that will report on all components is a power supply 'system' - more than just a power supply. A tool that will provide numbers so that others can add additional assistance. Tester does none of that.

Best price (under $20) for this commodity tool will probably be in Wal-mart. Required tool is sold as a commodity - much like screwdrivers. Tester is a unique (exotic) tool that does nothing useful for your problem.

If CPU is Intel, then a seized CPU fan would cause no harm.

is the mulimeter similar to an Ohm meter.

Random note: the CPU is AMD, not intel here

Multimeter measures ohms, volts, and amps. It displays a measurement with at least three digits. You would be using its DC Volt function; 20 volt range.

If CPU fan is not working, still, CPU would at least boot. If AMD processor does not overheat too fast, then damage would not occur. It would just crash.

However this is getting too far ahead. First get voltage numbers.

Attach black lead to chassis or push the probe into the nylon connector to contact any black wire (from power supply). Touch the red probe to purple wire. Read and record that voltage both before and when power switch is pressed. Do same for green and gray wire. Later, do the same thing for any one red, orange, and yellow wire. But first, learn what those first three wires report on the meter.

I must make money to get meter now

UPDATE:
I got the power supply replaced...
Still down checking motherboard and new power supply

Well you could not find $20 to by a multimeter, but found $60 to buy a power supply? Then you did exactly what was recommended as not doing? How do you expect to get the computer fixed when you follow your feelings rather than facts?

Meanwhile, even a defective power supply can boot a computer. How do you expect to confirm power supply integrity again without the meter?

Replacing a power supply based only upon wild speculation is, well, ... you tell me. Exact same reasoning proved Saddam had WMDs or that it was safe to launch seven Challenger astronaut to their murder.

You still need a multimeter if fixing the computer is your intent. Appreciate the value of what you just did. The value in making mistakes - we learn from them.

No I finally got a hold of a friend who does this sort of thing and he ran the tests and replace it.

Oh. So its fixed. I did not understand that part.

Damm you are a conspiracy theorist.:eek:

Challenger engineer Boisjoly tells story behind disaster at lecture series finale

Roger Boisjoly

Roger M. Boisjoly

Morton Thiokol's Organization
From the NY Times of 28 Jan 1988: Engineer to Get Award For Warning on Shuttle TheMercenary still routinely denies reality. It is called involuntary manslaughter - a total disregard for human life. It was only an accident where people remain in denial.

No, it is risk benifit ratio. It is decisions not make in a box by one person. It is various individuals who cried wolf in a case where they turned out to be right. There is not a single event of the magnitude of launching a shuttle to building a skyscraper to invading Iraq that does not have views which vary from the majority. None of that implies that there was some grand conspiracy, well except for those who want to believe there is. You obviously think otherwise.

Not quite, it is still in the shop sort of speak.

Well if your not part of the solution your part of the conspiracy.

A "risk benifit ratio" exists only where one has no basic knowledge. Meanwhile, while at a launch site, engineers who don't even work on the Shuttle were telling me of hundreds of problems (just a serious) that were also ignored. Roger's commission later listed many of those masisve problems - completely unacceptable - that engineers well understood - and were ignored.

After a murder of seven Challenger astronauts, the Roger's Commission listed 200 problems so major - so far beyond any "risk benifit ratio" - that the Space Shuttle could not fly again until all 200 were fixed; without exception. Many were the same problems noted by my engineering peers - who did not even work on the Shuttle.

"Risk benifit ratio". TheMercenary claims this number exists but does not provide the number? No numbers? Then he must be lying. Even engineers I worked with who did not work on the Shuttle knew it was worse than bad - well beyond any "risk benifit ratio". They were all that adament. "Mission Accomplished" also was justified using the same mythical "risk benifit ratio" reasoning.

The solution was easy. Air temperature had to increase so that the O rings would stay sealed - not fail as they almost did exactly same way one year earlier. But then a Shuttle and seven souls are completely expendible according the TheMercenary who has a 'risk benifit ratio'. Oh. TheMercenary did not know of that other near disaster - and he is still an expert? He says only he has the number. We cannot be trusted with the number.

TheMercenary demonstrates why people can get away with murder. An invented "risk benifit ratio" meant there was zero risk to those performing the murder. Notice what the number really measures. 'Risk benifit ratio' to the murders was in their favor. Screw the astronauts. Classic MBA thinking were only the "I" is important.