robb wrote:

i have a micro-controller board with 3 big 40DIP ICs, 10 or so 16
DIP support ICs. with 32v/8v/5v transformer supply that connects
to two bridge rectifiers {32v, 8v}a fuse links sit between
transformer and rectifiers, no schematic.

i believe the 32v shorted with 5V line and it blew one fuse
link. the fuse link was replaced with same and when powered all
three fuses blown.

So....where does one start to diagnose such a *big* problem ?

.
Only thing working is transformer outputs and it seems like i get
continuity hits everywhere i check
the board was built about 1985 (no SMT) it is about 14" x 5" has
3 x 40 DIP ICs and 10 or so 16 DIP support ICs, handful of
transistors many resistors,diodes etc,

ideas and help would be greatly appreciated

Well .... if the 5V supply went seriously high, the chances are it's all fried.
:-(

Have you tried powering the pcb from an external stabilised 5V power supply ?

The very first thing to look for is a clock oscillator (and valid reset signal).
Get the data sheets for those 40 pin chips, identify which one is the micro and
scope the relevant pin(s).

What are the 40 pin chip numbers btw ?

Graham