Here's an update.
I changed the Dallas chip, caps on the power input, some electrolytic caps near some chips but still nothing. When cooled down it boots normally, second, third etc boot after that nothing.
But, i got some compressed air, and managed to pin-point one area. When I blow/cool down the RAM chip, its starts every time :
IMG_0062 by
Elektroservis Hreš?an, on Flickr
The problem is that i don't have a soldering iron that can do SMD soldering, and re soldering might do more damage than good. None of the SMD caps looks bad/leaked.
Any idea why cooling the RAM chip makes it boot? Bad solder joint, or a bad chip perhaps? I tried pressing in the pins of the chips slightly, maybe a pin has a bad connection, but no change. It just takes a little cold air on the chip and it boots every time. . .