As long as the voltage on the SIDs is not ~12V you can't really expect anything but static and noise. So first up you'll need a working PSU. The easiest way to achieve that would be to get a 11-15V wall wart and feed the SID modules with it. Remove all the ICs, plug in the new wallwart, measure the voltages - if they're all good, and you only get 12V where you're supposed to, put the ICs back in and prepare for some SID goodness ;) Giving up is not an option :D