Ugh, doesn't sound good.... Others with more expertise may be able to help more..... But, you always want to check, and then double-check any power connections to any computer. Questions; why did you need more power to the 600 after adding a CF card? Don't they need less power than a comparable HDD? Second, couldn't you have used an old PC (AT) PSU to power the 600? (using a multimeter, and recyclcling the 600's PSU plug..... to make sure you have +12V going to +12V, etc. ??
Best of luck....
OK, worse-case scenario... you might find A600 mobo's on EPay.....
