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General discussion

Dead mobo/cpu/both?

Aug 10, 2005 12:56AM PDT

(I've searched the boards for this and found several similar posts, but none close enough for me to be sure they're the same, so I'll beg your indulgence)
A couple of weeks ago, my 3 year old home PC just quit in the middle of the day. My wife said it flashed a message - something about the floppy drive, then just went blank.
Cut to the end of the story (I'm trying to balance giving all the info & testing I've done vs. overload):
When I press the power button, the box goes on, all fans (case, power supply, & CPU) go on. The monitor does not display anything - the power light stays amber (it's on, but not receiving a signal).
The keyboard lights - all 3 of them - go on, and stay on.
There are no beeps, at all.
When the hard drive is connected, I can hear it spinning up - sounds normal.
(all of the below changes have been made both individually & together with each other)
I've tried disconnecting all peripherals, including all drives. By "disconnecting" I mean I removed the cables from the motherboard and the power cables from the drives.
I've tried replacing the power supply.
I've tried replacing the AGP Video card with a new PCI video card.
I've tried replacing the CPU (old one was a Celeron 1.7Ghz, new one is a P4 1.8Ghz).
This change actually made a small difference - before the change, when I held the power button to turn off the power, nothing happened - the power stayed on, and I had to flip the power supply's switch.
With the new CPU, holding in the power button for 5 seconds does turn the unit off.
I tried the old CPU in a new motherboard, and the new unit didn't even power on (well, it did, but very briefly).
I tried with no RAM chips in, and 1 at a time (of the original 2). And I tried them in different slots.

Is there anything else I can try?
The conclusion I have to reach is that the CPU & motherboard died at the same time - what are the odds? (that's not a rhetorical question - is there a good chance that happened?)
But I don't consider myself a hardware expert, so I'm wide open to additional thoughts and suggestions.

TIA.
PS - I'm trying not to x-post this too much, but I'm desperate for an answer, so I will probably post this on a couple of boards. Thanks for your indulgence.

Discussion is locked

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Dead mobo/cpu/both? addendum
Aug 10, 2005 1:11AM PDT

I forgot to mention a couple of other things I tried:
I replaced the mobo battery with a new one.
And I found the CMOS reset jumper & moved it to the other position, then moved it back.

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It is rare...
Aug 10, 2005 4:07AM PDT

that the cpu would fail causing the mobo to fail. If the cpu heats up enough it will fail w/o taking the mobo with it. Your systoms tell a different story. Your fans work so you are getting 12v through the mobo. So, what's left are the PCI channels and its chipsets. I'd say you need a new mobo and a cpu. Putting the Celeron on the mobo may have damaged it as well. Sorry.

and life goes on...

Jack

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The good news is...
Aug 10, 2005 11:02PM PDT

...that I didn't destroy the new (P4) by putting it on the old motherboard. The new CPU works just fine when I put it on the new motherboard.
So it looks like I need a new mobo for the other new CPU (which is another P4 I bought at the same time) - unless I can deduce that it's something other than the motherboard, but I've run out of thoughts as to what else there could be.
Now I have to move on to the next problem:
Being the genius that I am (just for clarification: yes, I'm being sarcastic), I stuck the old hard drive in the new unit to see that it would work. And I got so excited when it worked, that I tried to go into Windows XP.
I'm sure that (many of) you know that was a really bad idea (and now I know that, too). XP got past the bootstrap screen (the white bar at the bottom, before the Windows splash screen), then rebooted the PC. I can see a blue screen flash, but I can't read anything that's on it. It happens in every mode - I can't boot to safe mode, either.
(I'll post this to a new thread, but for anyone reading this hereHappy
(How) Can I recover from this mistake, to get XP running on this new box? Clearly, it's not going to be running on the old one - this is the hard drive from the old one, and the old one is brain dead.
The good news (I think) is that this is not an OEM copy of XP - I still have the original installation CD.
Thanks for the help.

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The good news is...
Aug 11, 2005 3:06AM PDT
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um i had the same problem kinda
Aug 11, 2005 3:41PM PDT

i havent fixed it yet but my uncle is microsoft certified so i thought he would know in my case every thign turned on but the screen was blank and the vid card ande ever thign was good he said it might jsut be you have a dead agp slot so try a new mobo. i still ahve to get another one so idk if thats the problem but it makes sense to me. but its just the crapy family puter and we already have one they use so thats why i havent fixed it yet my gaming puter is down right now Sad i posted on the forum i think i need a new mobo too for that one. my post is broken usb and motherboard or somethen if you can help me. its a very messed up problem