Parts for Tek 405 modules

I recently got a Tektronix TM405 with a FG502 function generator, DM502 volt meter, DC503 Universal counter, and a PS503 power supply.  Advertized as 'everything working'....yea, right.

A cursory inspection shows the FG502 to be dead, the DM502 to have a display that is constantly flashing 118.3 no matter what scale it is on.  The PS503 +/- outputs are dead.  
Now I need to go into troubleshooting mode.  I came across an extender cable from jamma boards so I can work the modules outside the enclosure.
I'll do the basic checking supply voltages, then  caps, diodes, etc.

So my questions at this point:

Are there any cross reference lists (pointers please?) for the Tek branded electronic parts?

Names of suppliers for some of the Tek parts?

Any common/well known failures & associated fixes for this PS?  

Any help is really appreciated.