how to diagnose blown psu, or, undiagnose it. - Techist - Tech Forum

Go Back   Techist - Tech Forum > Computer Hardware > System Upgrades
Click Here to Login
Closed Thread
 
Thread Tools Display Modes
 
Old 01-03-2009, 04:10 AM   #1 (permalink)
True Techie
 
Join Date: Feb 2007
Posts: 164
Default how to diagnose blown psu, or, undiagnose it.

while home for the weekend one of my tasks was to replace the PSU of an old (2001ish) emachine. I decided the best way to do this was to get my psu upgrade, and give the emachine a swap with my stock psu (gateway... something, newish, (2008)) I swapped my psu out, powered the computer up, works fine, swapped my old psu with the emachines, no response (same as the old psu). is that as good of a diagnosis as I am going to get? there is no way I can put the emchine psu in my new computer (24+4 connection), also, would it be a problem if I put a 28 pin connection onto a 24 pin mobo? I vaguely remember doing it in the past, but if I didnt, could that be a cause of the failure to power on? (though I didnt even get to bios screen)

thanks alot, and if one of the mods wants to close my other post, I cant figure out how to delete threads, but I noticed it was already modded by vern, so if he just wants to close it out, I've gotten my answers

thanks again again!

-Drew
__________________

drewjustforyou is offline  
Old 01-03-2009, 05:48 AM   #2 (permalink)
Master Techie
 
eyeCpc's Avatar
 
Join Date: Apr 2007
Posts: 2,074
Default Re: how to diagnose blown psu, or, undiagnose it.

First of all that old supply wouldn't even meet the minimum requirements of any recent board out. What was a 180-250w supply at best? You would need at least an atx 300w not an old AT type underpowered supply just to see a post.

It's likely that other things besides the supply failed on that old of a system. If the board had a battery to maintain the cmos that's probably long gone charly there. The board itself could have easily given out as well.
__________________

eyeCpc is offline  
Old 01-03-2009, 09:03 AM   #3 (permalink)
Patron
 
saltynay's Avatar
 
Join Date: Dec 2006
Location: West Coast, Singapore
Posts: 5,149
Default Re: how to diagnose blown psu, or, undiagnose it.

Wait a couple of days (for it to discharge) then take the casing off of the psu and look for dead capacitors or some other sign of electrical damage.
__________________
saltynay is offline  
Old 01-03-2009, 02:13 PM   #4 (permalink)
Running on empty.
 
chesirecat1701's Avatar
 
Join Date: Oct 2008
Location: Nicaragua
Posts: 403
Send a message via AIM to chesirecat1701 Send a message via MSN to chesirecat1701 Send a message via Yahoo to chesirecat1701
Default Re: how to diagnose blown psu, or, undiagnose it.

Quote:
Originally Posted by saltynay View Post
Wait a couple of days (for it to discharge) then take the casing off of the psu and look for dead capacitors or some other sign of electrical damage.
If you feel up to that task, working on this inside of PSU's isn't a task for the faint of heart. Ahh listen to me, a few days should be long enough for the Cap's to loose charge but either way still take caution
chesirecat1701 is offline  
Old 01-03-2009, 03:01 PM   #5 (permalink)
Master Techie
 
eyeCpc's Avatar
 
Join Date: Apr 2007
Posts: 2,074
Default Re: how to diagnose blown psu, or, undiagnose it.

Wear a pair of rubber gloves and touch the two contacts with an old screwdriver rather then getting belted across the room! Caps in a supply can still hold a lethal charge and are nothing to play around until properly discharged.
eyeCpc is offline  
Old 01-03-2009, 07:22 PM   #6 (permalink)
Seg Fault'n
 
Join Date: Jul 2005
Location: The dried husk where America came from
Posts: 5,801
Default Re: how to diagnose blown psu, or, undiagnose it.

I would not recommend fiddling about inside a PSU. But more to the point if the situation is that you have an emachine PC which does not work, you diognosed a broken PSU but you have changed that PSU out for a known good one from your gateway and it is still not working then maybe the emachines PSU is not what went wrong. Or have I got the wrong end of the stick with this one?
__________________


There are in order of increasing severity: lies, darn lies, statistics, and computer benchmarks. - diskinfo man page
"Get your money and let's go to court!" - Craig Mudie, MS
kmote is offline  
Old 01-03-2009, 09:30 PM   #7 (permalink)
Master Techie
 
eyeCpc's Avatar
 
Join Date: Apr 2007
Posts: 2,074
Default Re: how to diagnose blown psu, or, undiagnose it.

On any system that old you can easily run into multiple problems at once. bad or dead supply, board, cpu, memory, hard drive, video card, sound card. You may see a newer supply work on an old system like that but don't expect any old supply to run any recent build.

The questions here would be when was the last time it actually ran?, when did it stop and were you running any particular programs at the time? or was it sitting idle to simply switch off on it's own?, or refused to start up at all one day? How long was run daily if even run on any daily basis? could be another question to ask.

All that is rather pointless however since you would better off simply selling or swapping it off as a parts puppy unless you were able to replace the item that failed and run it for how long before... ?
eyeCpc is offline  
Old 01-04-2009, 06:21 AM   #8 (permalink)
Patron
 
saltynay's Avatar
 
Join Date: Dec 2006
Location: West Coast, Singapore
Posts: 5,149
Default Re: how to diagnose blown psu, or, undiagnose it.

Quote:
Originally Posted by eyeCpc View Post
Wear a pair of rubber gloves and touch the two contacts with an old screwdriver rather then getting belted across the room! Caps in a supply can still hold a lethal charge and are nothing to play around until properly discharged.
I told him to look for visible damage not using a amp meter and testing them directly thats just stupid I would leave it a week then wear rubber soled boots on a rubber mat easier to do then rubber gloves which in my house would never be at hand.
__________________
saltynay is offline  
Old 01-04-2009, 11:40 AM   #9 (permalink)
Wizard Techie
 
Lexluethar's Avatar
 
Join Date: Jul 2008
Location: 127.0.0.1
Posts: 4,708
Send a message via AIM to Lexluethar
Default Re: how to diagnose blown psu, or, undiagnose it.

Test the 'broken' power supply with a multimeter. That should tell you if the power supply is giving DC to the system board. If it is, look elsewhere for your problem.
__________________
-Vista SME
Lexluethar is offline  
Old 01-04-2009, 07:03 PM   #10 (permalink)
Master Techie
 
eyeCpc's Avatar
 
Join Date: Apr 2007
Posts: 2,074
Default Re: how to diagnose blown psu, or, undiagnose it.

Quote:
Originally Posted by saltynay View Post
I told him to look for visible damage not using a amp meter and testing them directly thats just stupid I would leave it a week then wear rubber soled boots on a rubber mat easier to do then rubber gloves which in my house would never be at hand.
Who said anything about using an amp meter?

You would isolate your feet and then handle a cap with your bare hands simply because you are standing on a rubber mat? You'll end up cooked royally since that wouldn't protect anybody. Your bare fingers would still be the conductor there unless you plan to handle the contacts with your feet.

Lexluethar had a more pratical approach there by simply testing the leads coming out of the supply for a voltage reading there without even opening up the supply itself.
__________________

eyeCpc is offline  
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
PSU Problem/Cooling Problem Like2game New Systems | Building and Buying 11 01-05-2009 08:46 PM
260GTX and another hard drive on my 460W PSU? jamaicaska New Systems | Building and Buying 7 12-07-2008 07:48 AM
PSU like acting like a vehicle... Chrysamere Hardware Repairs and Troubleshooting 4 07-01-2008 02:27 AM
PSU Trouble! Flipip Hardware Repairs and Troubleshooting 7 04-24-2008 04:19 PM
Question regarding mini ITX and recommended PSU 96300NAZ New Systems | Building and Buying 0 12-16-2007 10:29 PM



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 08:31 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.