Always use thermal paste and attach the sink with 462. Your cpu is gone possibly motherboard.

melbar wrote:

and finally I've put (at first try on this board), the socket 370 heatsink onto the CPU, only on top with it's weight, not fixed […]
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and finally I've put (at first try on this board), the socket 370 heatsink onto the CPU, only on top with it's weight, not fixed with the 3-point-clips at each side.

Also i didn't use thermal paste for this test.

Only for 2-3 seconds, i've seen a post screen or something, the heatsinks becomes really hot for my point of view - compared to the PIII for example...
The CPU smells also to something undefined, not really good...

It's dead, Jim ..I mean Melbar.

s370 and basically anything predating it, you can get away with not applying thermal compound.
Netburst has additional thermal protection.

Anything Socket A and no properly installed HSF? ...you'd be lucky if it had lived.
I kinda did the same with a Palomino. I installed the HSF properly, but had forgotten to apply any thermal paste. Black screen and magic smoke and that was it.

Your board is probably ok, provided you didn't leave the CPU burning for too long.

This happened to me once, except I forgot the heat sink entirely 😵 😵 😵
Kind of funny, this only happens with those types of AMD processors. If you do it with a Pentium III it'll work fine for a while and then die, but it certainly won't die after just 2 seconds.

Socket A CPUs do have a tendency to burn up, especially if you don't apply thermal paste or mount the heatsink properly. I'm afraid that the CPU is more than likely dead, but the board might still be alive. I'd grab another CPU and see if the board still works.

Although I had AMD CPUs in all of my custom built systems from 2000 through 2007, I have grown to really dislike the Socket A platform. The CPUs are incredibly easy to crush or kill in other ways, heatsink installation makes you wonder why on earth they would make it so easy to turn a board\CPU into useless junk without even doing anything wrong and all but the later models (and those known for overclocking) ran way too hot. Did I mention the stock coolers were junk as well? Lack of thermal protection exacerbates the problem even further. Socket 370 CPUs without heat spreaders have many of the same flaws, but at least they didn't put out so much heat and heat spreaders were eventually added.

Athlons and XPs were great bang for the buck CPUs at the time, but because of the above, I'm not a big fan of them anymore.