Failed mobo, or so I thought.

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For some reason when I booted up ny PC, I got no POST - just a blank
screen. The fans were working and I could hear the hdd spinning up and
the mobo had its diode light on, but nothing else. I removed all
components, including memory modules apart from processor and fans,
but still nothing happened, no beeps, not even a  memory error
showing. After scratching my head and assuming a mobo failure, I
removed the BIOS battery as a last ditch attempt. When switching on I
then got a series of nasty repetitive clicks, as the machine tried to
boot up. I switched off, replaced the battery and switched on again.
Then at last a POST showing memory failure. I replaced the memory
modules, graphics card and hdd. Finally my PC is back to normal.

The problem occurred after the machine went in to Standby on S3 (ie it
was in hibernation). When I hit the power switch most time it boots up
fine, but occasionally there are problems. So why did I need to reset
the BIOS, and does Stanby/Hibernation cause this kind of problem?

Re: Failed mobo, or so I thought.

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Standby/Hibernation shouldn't cause this problem. Since you've reseated
everything, I think its more likely that something came loose (or dust got
in the way) and in the course of taking everything out and putting it back
in you've cured the problem.

Do you have a spare power supply? If you are still having problems then the
power supply would be my first suspect.
Brian Cryer

Re: Failed mobo, or so I thought.

Several times I have noticed the filter caps on the MoBo breaking down, and
depending on how expensive a replacement is, it is sometimes cheaper to
replace the caps.  These caps are the larger ones on the board, not the tiny

I have replaced them on one of my computers since a replacement board would
have cost me 2 to 3 times what the cost of the caps were, but it depends on
your level of expertise, and how much you're willing to spend.  Usually,
when getting into the expense of buying this type of component, if you are
out of the "bell curve", i.e. either real old, or real new, it can be
expensive.  In my case, the board was quite old, and a replacement was going
to cost me double what I paid for the first one.

If you were to replace these caps yourself, be sure to use a static free
surface to work on, and static free solder sucker & gun.


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Re: Failed mobo, or so I thought.

On Mon, 04 Jun 2007 15:00:03 -0700, Frank Booth Snr

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I'd wonder if your power supply has a failing or inadequate
5VSB circuit.  If your board is jumpered to use 5VSB for PS2
or USB, you might try changing that from 5VSB to 5V, it
should be shown in the motherboard manual.  

Did you try only unplugging the PSU from AC for a couple
minutes?  If not try that next time.

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