[tlug] Hardware Problem: Check for Bulged Caps (was Re: Home Hardware Problem -- Please Check My Findings)

[jep200404 <jep200404@example.com>]

CL wrote:

> I think I have developed a need for a new motherboard ... 

A bad motherboard is just one of the possibilities for your grief. 

> Friday night I installed Xubuntu on the HDD, made a couple of changes to 
> the BIOS setup (hardware boot order, quiet fan, plug n' play software 
> notification) added Azureus and KTorrent, tested access to all drives, 
> then shut everything down.  Saturday morning, The machine started, 
> POST-tested the hardware, and kept spinning.  No video, no POST beep codes.

When someone says that after they did x, then the thing did not work, 
the obvious thing to say is to go back to what they had before. 
It's likely that you can not go back to the old OS. 
So, try booting a Knoppix 5.1.1 CD (even though below you 
swapped the HDD successfully). 

   http://torrent.unix-ag.uni-kl.de/

At the Knoppix 5.1.1 CD boot prompt, try something like: 

   boot: knoppix noswap

Also try running memtest. 

   http://www.memtest.org/

You can have a separate memtest CD, or just run the older version 
of memtest that is included on the Knoppix 5.1.1 CD. At the Knoppix 
5.1.1 CD boot prompt, try something like: 

   boot: memtest

> I have tested the hardware, by connecting the TV, keyboard and mouse 
> directly to the 2.8GHz machine and swapping in all major hardware from 
> the torrenting machine, including:
> 
> The HDD
> The DVD/CD player/burner
> The video card
> The PCI riser
> The memory
> 
> All work in the 2.8GHz box; separately (swapped one piece at a time) and 
> together (all installed in the box at once).

Good. 

Also try swapping the power supply. 

> My conclusion is that there is "something wrong" with the motherboard 
> that is beyond the reach of someone with a large, well stocked toolbox 
> and a circuit tester. 

You might indeed have a bad motherboard. You might also have a bad 
power supply or even some incompatibility between the new OS and your 
motherboard. 

Visually inspect the motherboard and power supply for bulged capacitors. 
This is _still_ a common problem. 

   http://en.wikipedia.org/wiki/Capacitor_plague

When I have a computer that is behaving wierdly, find 
bulged caps in the motherboard or power supply, 
and replace them, about half of the computers work just fine 
afterwards. 

Earlier this month I fixed an LCD monitor by replacing two 
bulged caps in the high voltage power supply for the 
flourescent lamp backlight. 

Be sure to disconnect your power supply from the power input and 
wait a few minutes before opening the power supply. Things are 
often crowded inside power supplies. Don't force anything. 
If you become frustrated, walk away and try away later. 
(I.e, Be patient and gentle.)