[ ss4 poweron after failure ]
> When I power down the system, disconnect it from the power-supply and
>then connect it again, the system will not switch on, because it is
>waiting for somebody >pressing the power-on-button.

I once had the same thing and solved it by loosening the power supply a
little and then putting part of a thick paperclip as a bar across the power
switch so that it is always "on".