Solve : Dead mobo/cpu/both??

1.	Solve : Dead mobo/cpu/both??
Answer» (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 - This is the first place I'm posting this and I'll try not to cross-post much, but it's possible I'll post one or 2 other places - thanks again for your indulgence.Try the following first: To reset the BIOS, take the following steps: 1. Power down computer 2. Take countermeasures against electro-static discharge 3. Remove computer casing 4. Inspect MAINBOARD for a CMOS jump switch or CMOS battery In case of CMOS jump switch: Follow instructions provided with the mainboard manual. In case of CMOS battery: I. Remove CMOS battery for approximately 10-15 seconds. II. After 10-15 seconds, place the CMOS battery back. 5. Power on system. *Do not power on the system when CMOS jumper is set to clear_cmos* or when CMOS battery is non-present.** If that does not work, and you have literally replaced or tested every hardware component that is installed, then I would take out the mainboard and inspect it for burn marks or other types of damage.Raptor, Thanks for the reply. I forgot to mention those: 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. I'm not sure I reset it for long enough, though. I'll try that one again. Thanks again. Quote ...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?)... The motherboard supplies the proper voltages to the CPU, the PSU supplies the "raw" voltages to the motherboard and drives. If the motherboard voltage regulator blew out, the cpu could indeed become damaged. Quote The motherboard supplies the proper voltages to the CPU, the PSU supplies the "raw" voltages to the motherboard and drives. If the motherboard voltage regulator blew out, the cpu could indeed become damaged. That's good to know, I guess. I hope I didn't BLOW out my new CPU (what are the odds of that, you think?) I'll look around to see if I've got any other mobos for socket 478, or buy a new one if necessary. Thanks for the info. My wife said it flashed a message - something about the floppy drive, then just went blank. Posted by: Groucho1062 Maybe the pc was trying to tell you something! M_2 disconnect the ide cable to the floppy drive! Quote My wife said it flashed a message - something about the floppy drive, then just went blank. Posted by: Groucho1062 Maybe the pc was trying to tell you something! M_2 disconnect the ide cable to the floppy drive! Merlin, Thanks for the reply. As I said in my original message, "I tried disconnecting the peripherals, including all drives" - cables & power. The floppy was among those peripherals (as were the hard drive, CD, etc.).How far does the pc boot>>>does it pass power on system test! Quote That's good to know, I guess. I hope I didn't blow out my new CPU (what are the odds of that, you think?) I'll look around to see if I've got any other mobos for socket 478, or buy a new one if necessary. Thanks for the info. All about the CPU is here: http://www.intel.com/design/pentium4/datashts/249887.htm I believe your CPU operates at a core voltage of 1.7V. Power supply provides +3.3, +5, +12. Voltage regulator on motherboard makes 1.7 from one or all of the three. Intel says: "...If the processor socket is empty, or the voltage regulation circuit cannot supply the voltage that is requested, it must disable itself..." Was the replacement power supply equivalent to the original and did you insure to connect the 4-pin 12V molex connector (required for P4 operation)? Did you try new CPU in new motherboard? Quote How far does the pc boot>>>does it pass power on system test! Again - I'm not hearing any beeps, and I'm not seeing any video, so I have to conclude that it's not getting to the POST. Quote Was the replacement power supply equivalent to the original and did you insure to connect the 4-pin 12V molex connector (required for P4 operation)? Did you try new CPU in new motherboard? That's tonight's project. New CPU(s - I BOUGHT 2 - 1 to replace the old one, one for the new motherboard) in new mobo, and the rest of the construction. On the off chance I damaged the new CPU (and how much would that suck!) can I damage the new mobo by plugging in the new (& damaged) P4? Because this is getting ridiculous! Thanks.Did you use artic silver paste on the cpu/s..........between the cpu/heatsink!... Info link:>http://www.buildyourowncomputer.net/step3.html or this link>http://www.datawaretech.com/Sounds like your RAM to me. Try a diffrent stick of RAM from the ones you have been using. Faulty RAM can give the symptoms you have. Quote Sounds like your RAM to me. Try a diffrent stick of RAM from the ones you have been using. Faulty RAM can give the symptoms you have. Frankie, Thanks for the reply. I guess that's possible, but I have 2 memory sticks in there, and tried them each individually, in different slots. At this point, I know the (original, Celeron) processor is bad. I've got the new processors (but not both at the same time) working in the new motherboard ( - at least that!), and when I put the celeron in the new mobo, it acts as though there's no CPU there - it powers on very briefly, then shuts down. Now I just need to determine (for sure) that the old mobo is bad, or could there be something else - yes, like RAM - causing it to not boot, even with the new processor. Thanks again.I know you say you have got 2 sticks of Ram that you have tried, but if you have another spare one about i would try that one. This is SOMTHING that happened to me. Have you tried the Ram in another computer. I would also make sure there is no dust in the Ram slots, give it a blow out and make sure the Ram is seated right. The only other thing i can think of is if it doesnt post (make sure you have the speaker connected to hear the beep). Is to disconnect all peripherals and system adaptor cards in the unit, except for the keyboard and monitor and see if it posts. If it doesnt post after doing all this. I would say there is a fault with your motherboard.

Answer»

(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 - This is the first place I'm posting this and I'll try not to cross-post much, but it's possible I'll post one or 2 other places - thanks again for your indulgence.Try the following first:

To reset the BIOS, take the following steps:

1. Power down computer
2. Take countermeasures against electro-static discharge
3. Remove computer casing
4. Inspect MAINBOARD for a CMOS jump switch or CMOS battery

In case of CMOS jump switch:

Follow instructions provided with the mainboard manual.

In case of CMOS battery:

I. Remove CMOS battery for approximately 10-15 seconds.
II. After 10-15 seconds, place the CMOS battery back.

5. Power on system.

Do not power on the system when CMOS jumper is set to clear_cmos or when CMOS battery is non-present.

If that does not work, and you have literally replaced or tested every hardware component that is installed, then I would take out the mainboard and inspect it for burn marks or other types of damage.Raptor,
Thanks for the reply.
I forgot to mention those:
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. I'm not sure I reset it for long enough, though.
I'll try that one again.

Thanks again. Quote

...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?)...

The motherboard supplies the proper voltages to the CPU, the PSU supplies the "raw" voltages to the motherboard and drives. If the motherboard voltage regulator blew out, the cpu could indeed become damaged. Quote

The motherboard supplies the proper voltages to the CPU, the PSU supplies the "raw" voltages to the motherboard and drives. If the motherboard voltage regulator blew out, the cpu could indeed become damaged.

That's good to know, I guess. I hope I didn't BLOW out my new CPU (what are the odds of that, you think?)

I'll look around to see if I've got any other mobos for socket 478, or buy a new one if necessary.
Thanks for the info.
My wife said it flashed a message - something about the floppy drive, then just went blank. Posted by: Groucho1062

Maybe the pc was trying to tell you something! M_2
disconnect the ide cable to the floppy drive!
Quote

My wife said it flashed a message - something about the floppy drive, then just went blank. Posted by: Groucho1062

Maybe the pc was trying to tell you something! M_2
disconnect the ide cable to the floppy drive!

Merlin,
Thanks for the reply. As I said in my original message, "I tried disconnecting the peripherals, including all drives" - cables & power. The floppy was among those peripherals (as were the hard drive, CD, etc.).How far does the pc boot>>>does it pass power on system test! Quote

That's good to know, I guess. I hope I didn't blow out my new CPU (what are the odds of that, you think?)

I'll look around to see if I've got any other mobos for socket 478, or buy a new one if necessary.
Thanks for the info.

All about the CPU is here:
http://www.intel.com/design/pentium4/datashts/249887.htm

I believe your CPU operates at a core voltage of 1.7V. Power supply provides +3.3, +5, +12. Voltage regulator on motherboard makes 1.7 from one or all of the three.

Intel says:
"...If the processor socket is empty, or the voltage regulation circuit cannot supply the voltage that is requested, it must disable itself..."

Was the replacement power supply equivalent to the original and did you insure to connect the 4-pin 12V molex connector (required for P4 operation)?

Did you try new CPU in new motherboard? Quote

How far does the pc boot>>>does it pass power on system test!

Again - I'm not hearing any beeps, and I'm not seeing any video, so I have to conclude that it's not getting to the POST. Quote

Was the replacement power supply equivalent to the original and did you insure to connect the 4-pin 12V molex connector (required for P4 operation)?

Did you try new CPU in new motherboard?

That's tonight's project. New CPU(s - I BOUGHT 2 - 1 to replace the old one, one for the new motherboard) in new mobo, and the rest of the construction.
On the off chance I damaged the new CPU (and how much would that suck!) can I damage the new mobo by plugging in the new (& damaged) P4? Because this is getting ridiculous!
Thanks.Did you use artic silver paste on the cpu/s..........between the cpu/heatsink!...

Info link:>http://www.buildyourowncomputer.net/step3.html

or this link>http://www.datawaretech.com/Sounds like your RAM to me. Try a diffrent stick of RAM from the ones you have been using. Faulty RAM can give the symptoms you have. Quote

Sounds like your RAM to me. Try a diffrent stick of RAM from the ones you have been using. Faulty RAM can give the symptoms you have.

Frankie,
Thanks for the reply.
I guess that's possible, but I have 2 memory sticks in there, and tried them each individually, in different slots.

At this point, I *know* the (original, Celeron) processor is bad. I've got the new processors (but not both at the same time) working in the new motherboard ( - at least that!), and when I put the celeron in the new mobo, it acts as though there's no CPU there - it powers on very briefly, then shuts down.

Now I just need to determine (for sure) that the old mobo is bad, or could there be something else - yes, like RAM - causing it to not boot, even with the new processor.

Thanks again.I know you say you have got 2 sticks of Ram that you have tried, but if you have another spare one about i would try that one. This is SOMTHING that happened to me.

Have you tried the Ram in another computer. I would also make sure there is no dust in the Ram slots, give it a blow out and make sure the Ram is seated right.

The only other thing i can think of is if it doesnt post (make sure you have the speaker connected to hear the beep). Is to disconnect all peripherals and system adaptor cards in the unit, except for the keyboard and monitor and see if it posts. If it doesnt post after doing all this. I would say there is a fault with your motherboard.

Solve : Dead mobo/cpu/both??

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