Power failure issue

Download and run memtest86+ from either http://memtest.org ot the UBCD (which contains several memory testers, as well as other usefull tools) from http://ultimatebootcd.com. Give it at least 5 passes if it doesn't fail on the first one already. If the memory looks OK remove everything non essential from the PC and run the PC in normal mode to find out if the problem persists. If it runs OK add the removed parts one by one and allways test it again.

I would think you need a power stablizer, such as the Opti-UPS SS1200 6-Outlet Voltage Stabilizer

Can be ordered online here:

http://www.geeks.com/details.asp?invtid=AVR-SS1200&cat=UPS for $19.95 (0n Sale)
http://www.newegg.com/Product/Product.asp?Item=N82E16842107125#DetailSpecs $21.95 in Black

Or you can look at a APC Back-UPS BE350U 350VA 200W 6 Outlets UPS which outputs exactly 110v plus power backup if the power goes out:

http://www.newegg.com/Product/Product.asp?Item=N82E16842101124#DetailSpecs $43.99 w/On Screen Monitor
http://www.compusa.com/products/product_info.asp?product_code=294980&pfp=SEARCH $39.99
For a bit more, this one has everything:

http://www.compusa.com/products/product_info.asp?product_code=50985986&pfp=SEARCH  w/On Screen Monitor

I don't think that this has anything whatsoever to do with the AC line power.  If there is a power problem, it's most likely an inadequate or failing power supply.  I don't want to get into a discussion of how switching power supplies work, but the bottom line is that they are incredibly insensitive to the incomming AC power within extremely wide limits.  All that they do is rectify the AC line and do minimal brute-force filtering (capacitor) to high voltage, unregulated DC, and the supply generates everything by switching this on and off at a very high frequency (tens to hundreds of KHz) through a pulse transformer.  The output is monitored at the switching frequency and the switching is "pulse width modulated" to maintain the proper output.  Because the frequency is so high, it can be very effectively filterned completely with relatively small capacitors.  It is VERY hard for power line problems other than extreme spikes, sags or dropouts to get through the supply; normally, you need to drop below 80 volts or so, or have total dropouts for several cycles to cause output interruption.

However, if you have any doubt about that, get a UPS.  You can buy APC UPS' for under $30 on sale, and a 350VA UPS will run almost any PC, notwithstanding that it seemingly exceeds the ratings (I've run pretty high-end PCs with 450 and 500 watt supplies from a 350 VA ups with no problems, and the UPS doesn't even report an overload (even during line drops), although such a PC is potentially twice the rated capacity of the UPS).  The newer UPS, with USB interfaces, keep "logs" of line events with digital line-voltage measurements, and the APC "Powerchute" software can access these logs.

I actually think that the problem probably has nothing to do with power or, if it does, that it's just a failing or inadequate supply in the PC.

I'd start with simple stuff first before spending any money

0.  Unplug anything thats not needed printer,speakers, joysticks.  (above post)
1.  Re-seat the RAM, Video Card, Sound Card, NIC, ide cables, SATA, etc.
1.  change outlet
2.  change room
3.  change power strip and or extension cord if applicable(i've seen the contacts melt toghter in relay switches)
4.  bring computer over someone elses house and verify problem
5.  If indeed it is your house, then buy any ups thats rated over 400 watts(or whatever your power supply max may be.)

Kind of strange problem, let us know what happens :)

I concur with Watzman and computerfixins.
However when a psu starts to fail, it can allow AC current to "leak" to the mobo.
What do you think happens to an electronic device that suddenly receives AC when it was designed to run on DC?
Not good.
Try and get a multi-meter and remove PSU then apply the following method:
http://www.gideontech.com/content/articles/196/1
http://forums.thatcomputerguy.us/index.php?s=f5170ccf6925e6b3fd150134f7d38019&showtopic=1120&pid=23345&st=0&#entry23345

Then test the "molex" plug contacts with the multi-meter: YELLOW=12V         RED=5V
If it reads below 12V on yellow, toss it. Another quick check that is not always accurate is to take the PSU apart, and check its capacitors, if swollen or leaking, its trash.
And while your at it, be sure and check the capacitors on the motherboard as well:
http://forums.anandtech.com/messageview.aspx?catid=32&threadid=1560063&STARTPAGE=2
http://www.badcaps.net/

Good luck.

just reinstall os and i hope every thing will work.
i would add ups just in case

Re: "However when a psu starts to fail, it can allow AC current to "leak" to the mobo."

That is not correct, at least not for anything that would be considered a "typical" failure.  There is total, 100% transformer isolation between the input and outputs of a computer power supply, and that isolation is tested to thousands of volts.  If there were not, first, it could not be UL approved, and second, there would be an electrocution hazard to anyone using the system and coming in contact with any part of it.  Certainly, there are lots of things that can and do happen when a supply fails, and the 2nd paragraph of your post is fine, but it would be extremely abnormal (and lethally dangerous) for any mode of a failing power supply to actually put AC line voltage onto any of the output rails of that supply.  The supplies are designed and tested to insure that this is simply not even a reasonably possible failure mode, and within the supply, there is a "primary side" and a "secondary side", and the two have no electrical connection whatsoever, the only connections being by very well insulated and totally separate transformer windings and an "opto-coupler" in the regulation circuit.

<QUOTE>That is not correct, at least not for anything that would be considered a "typical" failure.  There is total, 100% transformer isolation between the input and outputs of a computer power supply, and that isolation is tested to thousands of volts.  If there were not, first, it could not be UL approved, and second, there would be an electrocution hazard to anyone using the system and coming in contact with any part of it.  Certainly, there are lots of things that can and do happen when a supply fails, and the 2nd paragraph of your post is fine, but it would be extremely abnormal (and lethally dangerous) for any mode of a failing power supply to actually put AC line voltage onto any of the output rails of that supply.  The supplies are designed and tested to insure that this is simply not even a reasonably possible failure mode, and within the supply, there is a "primary side" and a "secondary side", and the two have no electrical connection whatsoever, the only connections being by very well insulated and totally separate transformer windings and an "opto-coupler" in the regulation circuit.
<END QUOTE>

Thats how I heard it once........ but since your knowledge of power supplies appears to supercede my own, I'll take your word for it.

we moved the computer to a different room and plugged in the monitor and computer, and booted up just fine. then we swapped the power strip with another one we had lying around, and it now boots up with the monitor and computer only. as soon as the keyboard, mouse and/or speaker are attached it goes through the reboot cycle.

still sound like an inadequate psu? Thanks.

No, it does not sound like anything related to power.  The keyboard, mouse and speakers don't draw any significant power at all (a fraction of one watt each for the mouse and keyboard -- speaker depends on what sounds, if any, are being produced).

good point watzman. i thought that was unusual too.

actually, now it's working properly. however as soon as somethign is plugged into one of the usb ports, the problem occurs. could this be a bios setting, or maybe the connection was shaked loose during the move?

thanks again

I have seen a few instances in which use of an old keyboard could cause very strange behavior somewhat like what you are describing.  But these were old IBM-type keyboards from the 1980's and early 1990's used on Pentium 4 systems.  The keyboards were PS/2 keyboards, but cause problems with the mouse & USB ports, and cause the system to lockup, sometimes not even to boot properly at all.  A few other people I spoke with saw the same thing with very old keyboards.

Other than that, it sounds like something in the system is just generally flakey.  The 1st thing I do in such cases is run a memory test (memtest86 or similar).  If the memory diagnostic will run for a couple of hours with zero errors, then it's more likely a software problem.  Do complete virus and adware scanning.  The ultimate fix for software problem is a complete reinstallaion, but that can be a huge task if there is a lot of software on the system.  I like to try it with a different, spare hard drive if possible, to retain the old system & all files in case that does not solve the problem.

If you have any suspicions about the power strips, replace them.  This doesn't sound or look like a power problem, but power strips are a couple of bucks.  Similarly, compared to CPUs and Motherboards and hard drives, power supplies are inexpensive and it might be worth trying a different, higher-capacity, known-good one.

<QUOTE>That is not correct, at least not for anything that would be considered a "typical" failure.  There is total, 100% transformer isolation between the input and outputs of a computer power supply, and that isolation is tested to thousands of volts.  If there were not, first, it could not be UL approved, and second, there would be an electrocution hazard to anyone using the system and coming in contact with any part of it.<End Quote>
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If this were completely true, why do some PSU's have voltage leaks to the ground of the case itself, causing a mild to moderate shock when you touch any metal part of the case???

I agree they are built that way, but over time, and moving around, bad transformers or components, problems can and do appear, I have not only witnessed this happening, but there a dozens of these occurrences throughout the Hardware section.  I don't think it is the power supply unless you are drawing more wattage than the PSU is actually rated for.  Many PSU's claim something like 400 Watts on the box and PSU label, but when you read the fine print, that may not be correct.  That is why you have manufacturers like Antec calling theirs "True Power" PSU's.

Here is an easy guide to how much you need for your PC:

http://www.jscustompcs.com/power_supply/Power_Supply_Calculator.php?cmd=INTEL or this one...

http://www.jscustompcs.com/power_supply

If you have a multi-meter (VOM) to use on the PS itself, to see if the output is to the motherboard specs...ie 12 VDC, 5 VDC...ect.

The main power to the board is a 20 Pin Connector, which uses these power modes:
Pin  1 - 3.3v                    Pin 11 -  3.3v
Pin  2 - 3.3v                    Pin 12 -  -12 v
Pin  3 - Common              Pin 13 -  Common
Pin  4 - 5v                       Pin 14 -  PS ON
Pin  5 - Common              Pin 15 -  Common
Pin  6 - 5v                       Pin 16 -  Common
Pin  7 - Common              Pin 17 -  Common
Pin  8 - PWROK                Pin 18 -  -5v
Pin  9 - 5vSB (Standby)     Pin 19 -  5v
Pin 10 - 12v                     Pin 20 -  5v

If you are using a wireless mouse, keyboard, or both, the RF signals could be interfering with other signals.  It's beginning to sound as though the motherboard itself could be starting to have problems, although I would check everything else first.

Many Apartment complexes have power problems, especially those who have their own substation.  Rather that just a power strip or plain surge protector, you may need a clean power strip.

http://www.monstercable.com/power/lineHTPower.asp for clean power.

Wiring in a home or an Apartment acts as antennas, in fact some broadband router/VPN's use electrical outlets to connect the main PC to another.

You can also try removing the power cable and hitting the power button to discharge any static electricity, remove the case panel, and check that all connections are secure.

Its a power issue caused byone of the following:
1- marginal power supply
2- apartment complex power probs
3- crummy power strip