Sudden boot problem

[ianw]

Hi all,

Came back today to find my PC screen had frozen up, on the screensaver, nothing would shift it which I found very surprising as it has behaved itself up 'til now. So I reset the machine. It had been on for >36 hours, has been done before and hasn't been a problem. On the restart all of the fans started up but I got no beeps and nothing on screen.

Some details - I built it myself just over a year ago, am running Gentoo Linux (kernel 2.6.9), quite a few minor/major software problems (which I expect now and again) but this is the first major hardware problem I've had with it. Specification:

Gigabyte K8VT800 Motherboard, BIOS has "Pheonix BIOS, BIOS D686" written on it
AMD64 3000+ CPU
512MB DDR400 RAM, 1 DIMM
XFX GeForce FX5200 128MB Graphics Card
160GB SATA150 HDD
Samsung 73V 17" TFT
and various CDRW, DVDROM, network card and modem.

after reading several posts in this, and other forums, have tried several things but nothing restores it to its former working glory.

- removed/disconnected all components from motherboard bar CPU, RAM and video card
- taken motherboard outside the case onto a cardboard box
- removed battery to clear CMOS, several times
- reseating the video card, several times

The final thing I noticed it doing, with the motherboard out the case, was for everything to power up when the PSU power was switched on, even without contacting the power on/off pins... that seemed really strange.

I've no idea after all this time why it's suddenly gone wrong, and part of the problem is I don't have another machine here to cross-check things... Has anyone any suggestions of other things I could try? Bar replacing the motherboard (which seems to be the most likely culprit)

Thanks in advance!

[nolander414]

Just found your topic, so i thought i'd repost my original thread inside yours...

I've had my computer for about 3 years now.  Just recently it was sitting idle on the desktop, and it suddenly shut down... as in it completely went black and the power went off.  Since then, I have not been able to turn it back on.  I've tried a number of things to fix it, and I think I may have narrowed down the problem.  
 
I've unplugged everything from my motherboard that isn't necessary, including the harddrive and videocard.  The only things left plugged in were the memory and the connector to the front power switch (and of course, the processor =]).  My motherboard has a 20-pin power connector and an additional 4-pin ATX processor power connector on the other side of the board.  When just the 20-pin is connected to the power supply, I am actually able to get power to the computer, as in the fans will turn on and various components will as well.  It just won't start up because the 4-pin connector isn't plugged in so there's no power to the processor.  However, when i turn it off, plug in the 4-pin ATX connector, and try to turn it on again, there's no power whatsoever.  Nothing comes on, not even the power supply.  My computer doesn't even get to POST or start beeping, it simply just sits there as if nothing has happened.  I know it isn't a power supply issue because I even went so far as buying a new one, but when everthing was plugged in the same problem arose.  It seems to me like it might be an electrical issue, but I'm just not sure.
 
If anyone is able to help, there are three things I would like to know.  One, is this a processor problem, a motherboard problem, or both.  Two, can the problem be fixed, or am I better off buying new whichever of those two is causing the problem.  And three, if I am completely off in my assessment of what the problem may be, please suggest anything that may assist in my identifying and fixing the problem.  
 
Hardware:
Turbolink 420w power supply
MSI-K8T Neo motherboard
Athlon AMD 64 3000+ processor
 
Thanks in advance for your help.

[IT-Guy]

These are two separate issues and should be kept that way...  It's too confusing otherwise.  On the original post, if you get a blank screen with no beeps and no post, it's most likely the memory.  I'd try replacing that first.

[Backdated]

To the thread originator:
You must disable all devices by disconnecting both power and data cables.
Use one stick of proven good memory.
Use a known good PCI video card.
Taking the motherboard out of the case can leave the ground potential floating in some areas of some boards - It's not advisable to do this without first ensuring that any grounding points are in fact, grounded.

To the thread hijacker:
Please start a new thread if you haven't already done so.