So what is dead - cpu or board?

I bought a new case at the weekend and it has digital thermometers for the cpu and hdd and an Intel Pentium 4 recommended 300w psu.

I have an Athlon 2100+ running on an Asus A78NX V2 and I connected the thermal probe for the cpu between the cpu die and the heatsink. At first the pc wouldn't boot, so I removed the probe from the cpu. When the pc did boot up, the video would not display properly when WinXP loaded the drivers, it looked like one of those Magic Eye pictures you see. I booted into safe mode and set the video output for default refresh on 800x600 but still the same problem. I then booted up in vga mode and although I got a picture this time, the pc hung. It then hung in the BIOS setup screen.

I removed the heatsink from the cpu and noticed there was some thermal paste from the heatsink across a couple of the capcitors on the cpu. I tried scraping this off but there was some residue that could not be removed.

Since then, the PC will not boot past the POST screen and when I access the BIOS screen there is nothing there but the options menu at the bottom of the screen.

I have tried the cpu in my previous board, Abit KX7-333, and the board will not boot at all.

So, is the cpu dead and could the thermal paste have been the cause of the problem, maybe the P4 rated psu is to blame or is it more lkely the board has been damaged?

Just when I thought I was out, they pulled me back in!
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  1. Quote:
    maybe the P4 rated psu is to blame

    Yeh, maybe it's sunspot activity, or perhaps jupiter isn't aligned correctly. There is no such thing as a P4 rated power supply. They lied. What you have there is a standard power supply with an ATX 12v lead, aka P4 compatable. But that tells you nothing about the rest of the supply.

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  2. Why not hope for the best? Try using a little rubbing alcohol on a q-tip to get the rest of the thermal paste off of the places it shouldn't be. Good luck.
  3. your cpu is gone my friend, NEVER, i repeat, NEVER put anything between the cpu die and the heatsink except thermal paste, that cpu was toast before you knew what happened. thermal paste on a capacitor shouldnt hurt anything, has happened to me before with no problems. the probe would not have allowed proper heat transfer, and in my opinion, toasted your cpu. try a new cpu and this time dont put the probe there, locate the probe near the cpu die on the underside of the heatsink with double sided tape.

    Fat, Drunk, and Stupid is no way to go through life Son.
  4. CPU is gone it only takes about 60 seconds or the boot cycle to damage a CPU.

    Intel CPU's have a built in overheat protection and will shut down automatically but AMD cpu's are notorious for melting down as they do not have this built in protection and rely on software and the system BIOS to prevent overheating.

    It sounds unfortunately that when you had the thermister ( Diode that measures heat Type J ) that you had the system up long enough to view the desktop and might have had it going for more then 5 minutes or so.

    The CPU has overheated and is no longer working that is to bad sorry to hear about it.

    Thermal paste is none conductive and will not effect (SMT) Surface Mount Components) Ceramic capacitors are very robust and seldom burn-out about the only way that can happen is if the motherboard takes a over-volt from a power supply. Ceramics are not effected by ESD failure and the ceramic resisters are not either.

    When a circuit board such as a computer motherboard is manufactured the components are placed off feeder reels onto the board by a Robotics placement machine. After that the board goes into a reflow oven that melts the silver/lead and reflows the solder and all the components melt down onto the tinned placement pads on the circuit board. The temperatures for this reflow process can exceed 100 Deg ( Fer to Celsius is X2+30 = )Example(40x2=80+30=110 C) but in most cases a 4 stage oven is used that ramps the temperatures up and down so they very rarely exceed 80 Deg but all the lead on the board melts smoothly around the components.

    The Footprint size of most Cap's and resistors in a computer are from the 603 to the 1206 size and are almost indestructible.
    The Thermister that measures the CPU temperature should be attached to the aluminums heat sink. However AMD heat sinks do not have a correct fastener to do it with.

    AMD CPU heat sinks have many fins in them that you can try to gently squeeze the thermister between two of the fins
    As aluminums can be welded and have electricity run through it for that purpose it will conduct heat or rather dissipate heat to specific levels much higher then your CPU temperatures.

    Aluminum because of its molecular structure will stop transmitting electric current at high voltages as the atoms that make up the element fill with a max charge then it stops conducting electricity. Great for airplanes and fittings on top of transmission towers Lighting has massive electric charges but it cant transmit them through the aluminium it becomes none conductive.

    Your Motherboard and other hardware devices should still be in working order and you should be OK after you get a new CPU. Yes I know money............

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