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Old 2005-11-21, 17:06   #1
lori1963
 

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Default pc wont boot

my pc was working great until I shut it down,
I took one stick of ram out to try in another system.
i put the ram back into the pc,. my pc always made a one beep noise when booting, now it doesnt do that and the only thing on the screen is the floating box, telling me too check monitor cables or ckeck pc.
i put in another video card and still the same thing, i made sure all ram was seated tight and checked all cables
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Old 2005-11-21, 18:18   #2
paulunderwood
 
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In order, the things to check:

1) The fuse in the mains plug -- the one you plug into the wall. Try the computer cable by plugging it into your monitor. If the monitor works then the fuse in the plug is okay.

2) Power suppy unit (PSU) may need replacing. This can be tested by putting it into another system. It can be checked by a person who knows what he is doing with a multi meter.

3) Motherboard -- can be checked by putting a similar processor in it.

4) Main chip (CPU) -- unlikely. This can be checked by putting it in a similar system

It looks as though you have tested the ram already. HTH
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Old 2005-11-21, 18:53   #3
smh
 
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Try booting the pc with only one stick of RAM.

I hope you did unplug the powercable before you put the memory back in there? Even if the pc is off, there's still some power on the main board.
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Old 2005-11-22, 00:12   #4
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memory can be swapped well standbuy voltage is applyed not recomended incase you short some bridges on the main board.
Also check the video card there might be an extra plug on it for power directly to the card.
Might susgest you clear cmos this can be acomplished by shorting pins 2-3 near the cmos battery (silvery round object) then shorting pins 1-2 back again. I might susgest you reseat all your cards memory and power cables this is also another common cause for problems.
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Old 2005-11-22, 02:05   #5
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Quote:
Originally Posted by paulunderwood
1) The fuse in the mains plug -- the one you plug into the wall. Try the computer cable by plugging it into your monitor. If the monitor works then the fuse in the plug is okay.
I hope that you know that on the other side of the pond, individual power cords do not contain fuses. House wiring is 110-120 Volts and typically given a 15 Amp circuit breaker; 20 Amp breakers are typically reserved for dedicated circuits for things with big motors. An electric clothes dryer or an air conditioner will be wired with a double breaker to provide a 220-240 Volt circuit with the appropriate maximum current.

At an office, I saw a paper shredder that was wired with 110 Volts, three phase. It worked well except that the outlet was wired backward. I tried to explain it to the appropriate person. The told me that it was quite normal to need to hold the shredder switch at the "R" position to have it work correctly.

In another office, the building was wired for 277 Volt lighting. It is more efficient, but one must ensure that one uses the correct lamps (bulbs) or fireworks follow.

The building had 480 Volt, three phase service. At peak load, the building probably consumed 20 or so kilowatts of energy. It was a mixed-use building with offices on one side and a distribution center on the other. The distribution center had conveyer belts with many motors. The data center had some pretty good sized UPS batteries and many blinking lights!

In the event of a power failure, we were told to disconnect the two service mains. The power company never restored all three phases simultaneously. A three-phase motor does not like to run with only one or two phases available. We learned this the hard way by burning out the motor in the range hood in the food service area. Unfortunately, the chosen way to get the motor down for maintenance was to have someone climb a ladder up into the range hood and lower the motor down on his back. Not something that one wishes to repeat unnecessarily. I think we needed a service call on an elevator for a similar reason.

Unfortunately, none of this helps Lori get her computer back up and running. Good luck, Lori!
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Old 2005-11-22, 09:14   #6
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Quote:
I hope that you know that on the other side of the pond, individual power cords do not contain fuses. House wiring is 110-120 Volts and typically given a 15 Amp circuit breaker; 20 Amp breakers are typically reserved for dedicated circuits for things with big motors. An electric clothes dryer or an air conditioner will be wired with a double breaker to provide a 220-240 Volt circuit with the appropriate maximum current.
Thanks for the info.

Any handling of computer electronics should be done with "static electricity" in mind -- use of an antistatic wrist strap is useful. I was under the impression that if you held the case as you removed memory then there was little potential difference between you and the memory.

One should also switch off the at the wall socket because there is still mains current going to the computer otherwise. Do you north americans have switches on your wall sockets?

On re-reading the original post, it looks like it might be the memory that is the problem. It could be that the memory got broken when he removed it, put it in another computer or put it back.

I know from experience that tracking down why a system does not work, requires a process of elimination by testing each part of the system in turn.

Good luck, lori1963. Let us know of your progress with getting this problem sorted out.
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Old 2005-11-22, 18:21   #7
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Quote:
Originally Posted by paulunderwood
One should also switch off the at the wall socket because there is still mains current going to the computer otherwise. Do you north americans have switches on your wall sockets?
There are some switched outlets. The switch is typically near the door to the room and they are used to control lamps. I would not recommend plugging a computer into one, though, because if someone tripped the switch: BOOM. Mini power failure.

Typically a switch would be on a surge protector or an outlet strip (a device with one plug and a bank of outlets; very useful for computer equipment that has a separate plug for every little function). Switching off the outlet strip would allow the equipment to remain plugged in (which would keep the chassis grounding intact) while isolating the power supply from the main.
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Old 2005-11-22, 21:07   #8
xilman
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Quote:
Originally Posted by JHagerson
There are some switched outlets. ...
I've visited North America a few times and sundry European countries ditto. I always find it amusing how many ways that the provision of electrical power in quantity has been implemented.

The US seems, to British eyes, to have a particularly cavalier attitude to electrical safety. Perhaps it's because 110V is intrinsically much less dangerous than 220V.

The British system, on the other hand, with every wall socket switched, every appliance plug fused and with plugs that can not be removed from the socket merely by pulling on the cord, seems almost paranoid (and those aren't the only safety features engineered in, believe me).

What I find especially strange, given the litigitious nature of American society, is that the US manufacturers of electrical fittings and equipment haven't introduced an obsession with electrical safety closer to the British model.


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Old 2005-11-23, 04:04   #9
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Quote:
Originally Posted by xilman
What I find especially strange, given the litigitious nature of American society, is that the US manufacturers of electrical fittings and equipment haven't introduced an obsession with electrical safety closer to the British model.
We Yanks have had a crazy relationship with electricity over the years.

After Thomas Alva Edison was able to perfect the light bulb and begin mass production, he started stringing up electrical wires and building generation plants in big cities. Edison's system was based on direct current (DC) which could not be easily distributed over long distances without great resistive loss. Ohm's Law states that EMF = IR (Electromotive Force [a/k/a Voltage] = Current * Resistance). The Energy Formula (usually referred to as the "Power Formula") is E = (EMF)I (Energy = EMF * Current), or by algebra E = I^2 * R. So, Edison needed to build a number of small generators near his customers in order to provide electric lights.

George Westinghouse came up with an electrical system that was based on alternating current (AC). AC has the benefit of being readily transformable into various voltages (through the use of a transformer). Westinghouse's system got around the resistive loss problem by transforming the energy of his generator into a high voltage. Where the resistive loss quadruples if you double the current, it diminishes to one-fourth if you double the voltage (E = V^2 / R, Energy = Voltage^2 / Resistance). Therefore, with AC one could build fewer, bigger generating plants out in the countryside and distribute the power where you needed it with high-tension wires.

Edison saw the threat that Westinghouse's system posed to his plan. After all, he had what we now term "first mover" advantage and he did not want to give it up. As an inventor, Edison started working with AC. He devised an electric chair as a means of execution. He marketed his device by saying that an inmate could be "Westinghoused" and thereby sent to meet his maker.

Of course, we know know that the decision to use 60 Hz electrical current was a particularly bad one. The human body is particularly suscecptible to injury from current at this frequency.

Commercial jet lines use 400 Hz AC, and have 28 volt DC power available as well. Critical uninterruptible power supplies have huge DC batteries as an ultimate backup if the primary and secondary generators do not start in a timely manner. In the basement of the local switching telephone switching office, there are batteries to provide the 50 volt DC current that provides dial tone to old-fashioned, plug in the wall telephones, if the power and the generators fail.

With the application of semiconductors to power management applications, we can now "transform" DC current through the means of a switching power supply. If you look at the specification for the power supply in your PC, it is likely to be rated to work over a large range of input voltages and frequencies. If memory serves, the power supplies for the Apple II computer were rated for DC through 80 Hz or so and from 90 through about 250 volts.

Given its choice, electrical equipment would prefer higher voltages (within the rated range) to lower voltages. When the voltage sags (think of a brown-out on a warm Summer day), the amount of current required to supply the energy required to run a piece of equipment increases, which increases the amount of heat generated by the equipment. Good UPS systems will their battery resources to boost the voltage back up to specification when it sags.

Always respect the voltage limits of your power supply. Many power supplies have a switch that will enable you to operate them in 110 volt or 220 volt environments. Don't mix them up. The penalty for doing so is that the foul-smelling magic green smoke that makes it go will escape.
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Old 2005-11-24, 04:03   #10
cheesehead
 
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Quote:
Originally Posted by JHagerson
We Yanks have had a crazy relationship with electricity over the years.
Ben Franklin started that with his crazy bare-knuckle-to-key-on-the-kite-string-during-thunderstorm investigatory method.

Quote:
Originally Posted by xilman
The US seems, to British eyes, to have a particularly cavalier attitude to electrical safety.
Well, Ben lived to a ripe old age and got lots of elementary schools named after himself, so ...

Say, there's an idea for an alternate-history book! What if Franklin had always been sent to Britain instead of some time to France? Would Brits have had a significantly higher rate of death by electrocution, and simpler appliance plugs, than they now do? Oh, wait ... that would require that Cornwallis have successfully evacuated at Yorktown, or something like that. Never mind ...

Last fiddled with by cheesehead on 2005-11-24 at 04:16
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