[Kenwood] PS-50 help?

[Avi - Modi'im Orchards]

OK, I know I'm being lazy ... I'm looking for a "been there, done that" 
shortcut before I start to unsolder all the active devices and test them one 
by one ... forthwith the symptoms:

the supply has been loafing along for years running auxilliary equipment and 
gathering dust (admonishments accepted) and recently gave up the ghost. 
Symptoms are blown main (240v) fuse as soon as power switch is turned on, 
xfrmr primary shows about 5.5 ohms, secondary, still wired to the bridge 
rectifier, almost no resistance.

I blew/vacuumed out all the dust, no obviously smokeless components, but I 
recall once about ten years ago I went through this and di have to replace 
some small components on the PC board, but couldn't find any notes on what I 
did (and yes, my knuckles are sore from me rapping on them). I do recall 
more than once going ALL THE WAY in there and dismantling the fan motor so I 
could clean and lube the bearings ...

Any hints/suggestions/pointers? What kind of resistance readings should I 
be seeing across the different poles of the pass-transistors, after 
disconnecting them from the rest of the circuit? how about the diode bridge, 
or that discrete regulator circuit? The thing seems built like a tank, so 
worth rejuvenating.

Thanks in advance for any and all pointers.

-avi 4X6UA