Jump to content


 


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.


Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.

Photo

K7som+ And Duron 1.3 Ghz, Do Not Even Power On


  • Please log in to reply
6 replies to this topic

#1 novirusplease

novirusplease

  • Members
  • 142 posts
  • OFFLINE
  •  
  • Local time:09:28 AM

Posted 17 May 2006 - 05:49 AM

I purchased a second hand motherboard K7SOM+ and a Duron 1.3 Ghz separately (I had a K7SOM+ with a Duron 1.2 Ghz welded onto it which did not work so I bought another one). I do not know the initial state of these MB and CPU but visually they seem ok as no burning, leaking or even dust is to be noticed.

I assembled them together and installed it into my old case. Unfortunately, nothing happens when I switched on the PC. I first thought that I wrongly connected the power cables but according to the manual it is ok. I actually tried all positions that have to do with power as it did not work. Then I thought that the power supply was broken so I connected the motherboard onto another case which used to work. Nothing happened again, the cooling fans did not even rotate, no noise, no display, nothing.
Is my motherboard broken? Or is it my CPU?
How could I check and repair?
Guidance is highly appreciated.

BC AdBot (Login to Remove)

 


#2 pascor22234

pascor22234

  • Members
  • 403 posts
  • OFFLINE
  •  
  • Local time:10:28 AM

Posted 17 May 2006 - 06:48 PM

If you installed the motherboard in 2 different cases and the fans did not spin then the probability of having 2 bad power supplies is slim. Most likely what is happening is that the motherboard is bad. The power electonics on a motherboard can go bad and cause a short on one of the power rails. Power supplies are generally smart enough to sense a shorted output and then shut down all the outputs to avoid further damage. Sometimes the fans will get a small amount of power before the supply shuts itself down and the fans will move very slightly.

The likelihood of the CPU having a short is low but you might try starting the system without the CPU installed to see if the fans then spin.

#3 novirusplease

novirusplease
  • Topic Starter

  • Members
  • 142 posts
  • OFFLINE
  •  
  • Local time:09:28 AM

Posted 18 May 2006 - 01:19 AM

Many thanks for your reply.

Indeed, the fan does spin a fraction of a second in both cases before shutting down. In a third case (old low-cost dating from 1998), it boots up normally but a part of the motherboard (close to the mouse a printer port) gets very hot within a few seconds which seems to confirm your diagnostic.

T motherboard looks very clean and visually there is no hint of any damage or foreign body which could cause a short-cut. What can be done to solve the problem?

#4 acklan

acklan

    Bleepin' cat's meow


  • Members
  • 8,529 posts
  • OFFLINE
  •  
  • Gender:Not Telling
  • Location:Baton Rouge, La.
  • Local time:08:28 AM

Posted 18 May 2006 - 01:22 AM

When you installed the processor did you use thermal paste between the processor and the heatsink? If not you may have burned your processor.
"2007 & 2008 Windows Shell/User Award"

#5 novirusplease

novirusplease
  • Topic Starter

  • Members
  • 142 posts
  • OFFLINE
  •  
  • Local time:09:28 AM

Posted 18 May 2006 - 02:04 AM

Yes, a thermal paste has been used between the CPU and the heatsink. The previously mentioned heat does not come from the CPU but from other components that are between the CPU and the ports.

Guidance is still highly appreciated for this probable short-cut porblem.

#6 DaveM59

DaveM59

    Bleepin' Grandpa


  • Members
  • 1,355 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:TN USA
  • Local time:08:28 AM

Posted 18 May 2006 - 05:37 AM

Take a good look at the larger capacitors on the motherboard. Do you see any bulging on the tops? Another sign is leakage (brown ooze) from the capacitors. It may not be much, a magnifying glass will help.

For pictures, go to

http://www.badcaps.net

Lots of info there also.

Whether it's caused by bad caps or not, the fact that you can get the board to work (sort of) with an old "dumb" power supply seems to confirm that there's a short somewhere.

I would try the processor in a "known good" mobo just to confirm that it is still okay. If the motherboard is bad there is no economical fix unless it _is_ the capacitors. If you're good with a soldering iron they can be replaced. The website I mentioned has lots of info on that.

#7 novirusplease

novirusplease
  • Topic Starter

  • Members
  • 142 posts
  • OFFLINE
  •  
  • Local time:09:28 AM

Posted 21 May 2006 - 02:37 AM

Many thanks for all help.
It just does ot work. I will just throw this MB away (to recycling of course).




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users