I found an old mainboard.
Nothing fancy, it's a ECS K7SEM with a Duron 850 MHz soldered on the board, so no socket, and an integrated video / lan /audio / usb Sis 730 chipset.
Of course, it doesn't work.

The power supply on the VRM looks good, the power led lights on, the fan spin, but nothing else, not even a beep.
I've checked the ESR of all capacitors, they look good.

The thermal paste was so hard that the cpu was stuck on the heatsink. As a result, it's been damaged, and a part of what I think being a capacitor broke.
This could be the reason why nothing works.

Does anyone knows what components are on a Duron ?
I tried to mesure with a ohmeter and a capacimeter, but I can't get any valuable result.

The half broken component is on the left, easy to see.