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Symptoms of failing PSU ?

DEll XPS400
April 12, 2008 at 09:19:49
Specs: WinXP MCE 2005, P3 750MHz 256SDRAM

I posted about the problem earlier of my kids PC suddenly failing ! The symptoms are the PC are it wil suddenly freeze up ,all the fans on the PC will continue to work however no display the monitor will shut down and the lights on one of the CD drives will stay on ? This PC that was purchased in 2000 in a small form factor tower and the P.S. U. is a 145W ! Since purchasing the PC I have added sound card a graphics card and a slot fan for extra cooling . However I installed these upgrades years ago and the PC ran very well untill just a couple of months ago when it suffered this major H.W. failuse ? I believe its a power supply thats failed yet giving off enough power to keep some of the items running
parts running for instance the system fans ,the two drives a DVD-ROM and a CD-RW however the drives trays will not open one of them as I stated is giving off lights ? I have ordered another small form factor 145W P.S.U. for $22.00 + S&H ! Any special instuctions when installing the small form factor P.S.U. would be greatly appreciated .I've been told the pwr to the M/B. should be a 5V rail ,the P.S. comes with a 20 pin connector IDE cable ! Thank You and any info greatly appreciated !
Thank You ,Nick

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#1
April 12, 2008 at 09:26:21

Nick, didn't you experience issues with the power in your housing? If so line voltage variations can weaken a PSU.

I don't know how much these smaller PSUs should cost but $22 dowsn't sound like a quality unit. What is the actual form factor of the PSU? I suggest you search for a unit with more wattage.


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#2
April 12, 2008 at 10:05:29

I agree that $22 doesn't sound like enough to pay for a quality unit. Unfortunately, Nick has a tendency to "shoot 1st & ask questions later".

A couple of questions about these upgrades you did. Why was a PCI sound card necessary...doesn't the board have integrated sound? And why the PCI slot fan? Also, optical drives don't really put a strain on the PSU unless you're using them...but why do you have 3 drives, "two drives a DVD-ROM and a CD-RW"? The more crap you jam into a case (especially a SFF), the harder it is to cool.

You obviously didn't understand the explanation that was given to you about PSUs. Basically, a PSU converts AC to DC, then breaks the DC down into different voltage rails. The 3 most important rails are the +3.3v, +5v & +12v. The +12v rail is generally used by anything with a motor...fans, HDDs, optical drives. Modern systems also use the +12v rail for 100% of the CPU power plus it's also been tapped for video cards.

On older systems (prior to the P4), the +5v rail supplied 100% of the power to the CPU, therefore with older ATX PSUs it was common to see a fair amount of amperage dedicated to the +5v (30A+) but only a minimal amount on the +12v (10A+/-).

Based on your previous posts, the PSU is probably not the problem. Whatever happened to your plan to temporarily try a full size 350W ATX PSU to see if it corrected the problem(s)?


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#3
April 12, 2008 at 11:56:53

".....however the drives trays will not open..."

Optical drives require 5v, as does your floppy drive and some other components includung USB.
If your optical drive trays don't move, it's quite likely your floppy drive and USB ports don't properly work either.

The drive trays moving in or out when you press the button on the front of them only requires they be connected to a properly working PS and the computer is running - the data cable does not have to be connected, and they should do that even if the mboard isn't working properly.

Your PS is probably either.....
- putting no +5v at all, or putting out +5v but it's actual value is too low.
- OR - the actual voltage that is supposed to be +5v may be way too high - that can fry the PCBs on optical drives and floppy drives in a short time. Their leds may still come on, but they don't work properly otherwise.

I've seen cases where a PS is putting out no +5v at all, yet the hard drive and mboard still work fine, aside from the USB ports if applicable.

Your fans use +12v but they are much more tolerant of the actual voltage being too low or too high.

Failing power supplies are common and can cause your symptoms.
Check your PS.
See response 4 in this:
http://www.computing.net/hardware/w...
They often still partially work, yet they won't allow the computer to boot all the way.


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Related Solutions

#4
April 13, 2008 at 05:50:52

Manufacturer: STARTECH.COM
Mfg Part#: MICATXPOW145
Buy.com Sales Rank: 49489



If you''re looking for a smaller-sized power supply to fit space confined systems and unique applications, then the MICATXPOW145 is the power supply for you. The MICATXPOW145 is guaranteed compatible with Intel Pentium and AMD processors and designed for an extra long-life. The MICATXPOW145 power supply ensures stable system performance, using an automatic temperature control fan to move hot air away from sensitive components. A superior power filtration system is achieved through an EMI/RFI power filter. Low noise/ripple as well as short circuit protection are additional reasons why this is the ultimate power supply for system stability.


Features Fans Sleeve Bearing 80mm Single
Manufacturer Startech Computer Products
Standard Warranty 2 Year
Manufacturer Part Number MICATXPOW145
Input Voltage 115V AC to 230V AC
Weight 1.89 lb
Manufacturer Website Address www.startech.com
Product Name 145W AC Power Supply
Current 8A @ 3.3V DC - Output Current
14A @ 5V DC - Output Current
5.5A @ 12V DC - Output Current
0.3A @ -12V DC - Output Current
1A @ 5V DC - Standby - Output Current
Output Power 145 W
Product Type ATX12V Power Supply

Hi to all ,hope everyone is enjoying a relaxing Sunday ! The reason I went ahead an purchased the 145W small form factor P.S.U. is becasue it has the same specs as the one now installed in my P3 that has worked for 8 years . THe 350W I was unable to use becsue I could not one get it to fit the smnall form factor tower and two trying to hook it up from the out side of the case would not allow the cables to reach so I could connect them ? Finding a local shop that supplies cable extensions is not easy ,so Iam hoping this small form factor power supply would fit inside the case .It sholud ,if not Iam going to be very careful with the packaging so if I must I can take advantage of my 30 day return policy ! Well the P.S.U. should arrive Tuesday and I plan on attempting installation right away ! I will keep those interested posted on the out come . I feel confident that this is the problem with this old P3 ! Also the reason for the sound card is because the intergrated sound AC97 would not work ,I tried trouble shooting it with he help of a technician and they actually brought over the Sonic Impact S90 PCI sound card after being completly baffeled by being unable to get the AC97 intergrated sound to work ,he did not even charge me ,and the sound was a great improvement over the intergrated sound when it was working ,then the AC97 started working only when it felt like it ,then it stopped working completely ? Sound cards back in 2000 where almost always better then a intergrated sound ,that may have change it recent years ? Well wish me luck ,I need it HAHA :-) Again any links to P.S.U. installation guides would be greatly appreciated !
Take Care and Thanks ,Nick


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#5
April 13, 2008 at 06:15:58

Hey Guys ,
Nick Again ,I feel the symptoms my old P3 750MHz is giving off, points to the most likley culprit being the power supply. The reason I went with a 145W unit is for a couple of reasons ! #1 the price point ,I do not want to invest alot into getting this old work horse up and running ,may just pop for a refurbished P4 with WinXP! Also this system worked fine for 8 years with a 145W P.S.U. , so I do not see why trying another one at these specs would be a prob ,I certainly do not plan on using it for 8 more years! Iam going to unhook the slot fan and remove it ! Just a few things that came to mind after I posted my reply above . Also the link Tubessandwire only reassured me that its most likley the P.S.U. ! P.S.U. Specs>Manufacturer: STARTECH.COM
Mfg Part#: MICATXPOW145
Buy.com Sales Rank: 49489



If you''re looking for a smaller-sized power supply to fit space confined systems and unique applications, then the MICATXPOW145 is the power supply for you. The MICATXPOW145 is guaranteed compatible with Intel Pentium and AMD processors and designed for an extra long-life. The MICATXPOW145 power supply ensures stable system performance, using an automatic temperature control fan to move hot air away from sensitive components. A superior power filtration system is achieved through an EMI/RFI power filter. Low noise/ripple as well as short circuit protection are additional reasons why this is the ultimate power supply for system stability.

Features Fans Sleeve Bearing 80mm Single
Manufacturer Startech Computer Products
Standard Warranty 2 Year
Manufacturer Part Number MICATXPOW145
Input Voltage 115V AC to 230V AC
Weight 1.89 lb
Manufacturer Website Address www.startech.com
Product Name 145W AC Power Supply
Current 8A @ 3.3V DC - Output Current
14A @ 5V DC - Output Current
5.5A @ 12V DC - Output Current
0.3A @ -12V DC - Output Current
1A @ 5V DC - Standby - Output Current
Output Power 145 W
Product Type ATX12V Power Supply

Again Thanks to All
Nick
"Only those who risk going too far can know how far they can go."
-- Unknown source


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#6
April 13, 2008 at 07:48:55

Startech makes decent PSs. I have/have had several standard sized Startech PSs and none of them have failed - some are 10 years old or more.

"Iam hoping this small form factor power supply would fit inside the case "

Go to the Startech web site and look up it's specs - the dimensions are probably specified.

The most likely thing that may have happened is the fan in the original PS wasn't up to snuff anymore and the PS overheated, or it was damaged by the wiring problems where you are that you had.

"the AC97 started working only when it felt like it ,then it stopped working completely ?"

That may be directly related to a faulty PS - e.g. it may require +5v too.


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#7
April 13, 2008 at 08:01:37

Buying a larger case would have been the better option if you intended to run the normal amount of hardware in the case. 145watts doesn't sound like suffiecent power for the hardware you have.

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#8
April 13, 2008 at 08:20:45

He hasn't added any significant load to his system, he hasn't changed the mboard, and lots of older computers work fine with a 145 watt PS.

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#9
April 13, 2008 at 08:40:32

tubes

While I generally agree with you the fact of the matter is that the original system was configured to run without the sound card, graphics card and fan. Once Nick was faced with the need to buy components my belief is he would have been better off to buy a larger case and use the PSU he wanted to install externally insted of buying another 145watt PSU. The newer PSU may of may not have the same specs and that amount of wattage is marginal at best.


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#10
April 14, 2008 at 12:21:37

Look at those specs!

8A @ 3.3V DC
14A @ 5V DC
5.5A @ 12V DC

Each HDD or optical drive accounts for about 1.0A & each fan in the system (case fan, CPU fan, video card fan, PSU fan, etc) accounts for approx 0.25A each. Add em up...you've gotta be damn close to 5.5A, if not exceeding it.

14A doesn't seem like much on the +5V either. I don't know how much wattage a P3 750MHz pulls, but the max available on the +5V rail is only 70W (5V x 14A). And there are plenty of other devices that "nickel & dime" the +5V rail. It all adds up. You should always have some reserve...you certainly don't wanna be running at max capacity the majority of the time.

Have a look at the chart near the bottom of this page:

http://www.firingsquad.com/guides/p...

How do the amperage specs of the new PSU compare to the old PSU specs?


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#11
April 19, 2008 at 06:35:58

Well I refused to accept delivery the 145W micro size PSU ! After doing something I should have done B/4 even ordering this PS I checked the dimensions of the power supply and it was much to small. My tower is a mid size tower ,this power supply is for one of those really small micro form factor . What Iam going to do now is pull my P.S first get the exact size of the unit and then I believe I will look for a affordable 250W ,or something with slightly higher capacity then the 145W ! Also I want to make sure the new power supply has the correct amount of connectors and the right number of pins on the connection to the M.B. ,I need a 20 pin ATX connection not the newer 24 pin ! I apoligize after all of you took time to reply on the P.S. I ordered that its now a non issuse as far using a 145W P.S. ! My mid size tower still needs a smaller then normal P.S. ,because the 350W I already have is to big and will not fit :-( my tower in the P3 is called a mid size, the tower on my new Dell is a full size with alot of room for expansion ,its really a great tower ,already set up for a second internial H.D. ,when adding my TV Wonder Elite PCI card I never had to touch a screw driver ,its to hard to discribe how it works however its like a lever kind of lock down system for add on cards ! As you can tell I really like my Dell XPS400 !
Thanks to All
Nick

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#12
April 19, 2008 at 07:48:53

"I need a 20 pin ATX connection not the newer 24 pin !"

Most newer PSs have all possible connectors you may need, and a dual purpose main connector - 20/24 "pin" - it has a 20 position part, and a 4 position part - the 4 position part can be clipped on to the 20 position one if you must connect to 24 pin mboard connector; otherwise you unclip the 4 position part so you can use ithe 20 position part in a 20 pin mboard socket.

Find the Dell part number for the PS and/or the make and model of the PS and search with that to find one that is the right physical size.
e.g. http://www.power-on.com


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#13
April 19, 2008 at 08:46:27

Hi Tubesandwires,
I'm sorry if I confused you ,however my Dell is not the PC that needs the PSU,its my old P3 750MHz running WinMe . I used that PC for 6+ years B/4 giving it to my kids 13 and 11 after I purchased my new Dell XPS400. On what you said reguarding the 20 pin with the extra 4 pin ,I had noticed that with most of the PS I had looked at it had that setup ! I added some hardware to the old P3 and the 145W P.S.still worked, it may have lasted even longer if I did not install a CD-RW a Graphics and Sound card and a slot fan ? Thank You for your reply , you always provide usefull information ,I copied the link you provided me to my favorites and after I pull the old failing PSU and get the dimensions I will go back to that site and see what they have to offer !
Thank You Again
Nick

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#14
April 19, 2008 at 09:20:52

"I'm sorry if I confused you ,however my Dell is not the PC that needs the PSU,its my old P3 750MHz running WinMe ."

Oops on my part.
In that case, use the make and model of the PS to search with.

" it may have lasted even longer if I did not install aCD-RW a Graphics and Sound card and a slot fan ?"

Those don't add a significantly larger load to your system - 145 watts capacity will still handle that no problem.
You can see the optical drive doesn't use much power by looking at it's specs or the label on it, and it uses almost nothing when you aren't actually using it.
I know somone who has a HP system that has even less PS capacity and it works fine with a similar mboard with a 1 gb Celeron, an added video card, and two optical drives.
The most likely thing is the PS was damaged by your AC power problems, or the fan in the PS can no longer spin at it's designed max speed and the PS overheated and damaged the PS eventually causing it to fail.


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#15
April 20, 2008 at 08:11:17

Hi Tubesandwires,
Once again thanks ! Have a relaxing Sunday ! Everyday is Family day, however for my Family and I we use Sunday as a special day of spending it together ! Go to a movie do a little shopping and make a nice dinner ,tonight its filet steaks ! Mmmmm good ! Hope your not a vegeterian,opps !
Take Care ,Nick

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#16
April 20, 2008 at 08:39:22

"Hope your not a vegeterian,opps ! "

I'm not, but how often and the amount of meat I eat is moderate.


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#17
April 22, 2008 at 07:09:17

Hi Tubesandwies,
Actually thats the same with me, eating a steak is a occassionial treat not a weekly habit ! Iam 100% Italian/Americian and I love pasta and can eat it every day and never get sick of it ! Not to mention the many other Italian dishes ,Thia foods ,Asian etc.etc.etc.
Take Care ,Nick
P.S. I need to go on a diet !

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