While it is common to always blame the PSU and capacitors in any Amiga failure, making a jump to the CS MKII may be premature as they are hardy until you start playing with upgrading them.
As you did, start at the basics and strip away everything including fast ram, HDD, and daughter board. Use another CPU card if you have one and see if you get a boot screen. If you want to test your PSU, do it connected to the motherboard -- underload. Testing the motherboard with another PSU will help.
If you think it is the CS MKII, Stan Selak (Stachu100) on the boards can repair it, for the motherboard, you can have the caps replaced by a lot of folks, but a full diagnosis and repair, I recommend Anthony Hoffman (very fast turn around).
