it seems like either the power supply is unable to supply enough current or (more likely) there is something on the board shorting the 5V rail. You need to STUDY the Clays guides very carefully OR get some professional assistance to find your faults.
There are plenty of places you can have the board checked out and repaired.
That would be my advice if you are not technically inclined - get one machine going and learn to fix the smaller problems first before tackling something like this that is likely to be far more serious and also, you may end up causing more damage or worse - make the board UNREPAIRABLE at ALL!
