This is my first newsgroup post so maybe I could ask for some help
from the newsgroup. Please feel free to suggest if there is another
newsgroup full of Tektronix gurus.

Is there anyone who has experience of repairing a Tektronix TDS 460 or
same series.?
( 4 channel 350MHz DSO )
Mine shows an acquisition fail in the self test. It behaves OKish in
free run outside the waveform trigger region and one gets an
untriggered free running trace activity on screen.
However when the trigger level is in the correct active part of the
waveform no triggered capture takes place..ie the trig light goes
on..good and the waveform disappears..not so good.
Having tried to read up any leads from the web I suspect a capacitor
may have gone down in either the trigger circuit or on the a/d
acquisition board.
The snag is that these scopes were module repair only as far as I can
tell,
so the usual wonderful Tek service manuals which I now have, have no
PCB level schematics. I have yet to disassemble the beast, but some
pre-advice would be great if there are any stock faults that develop
with these scopes..like me I guess they are getting on a bit! My 475A
still keeps going well.

Any help here would be very gratefully received.
Thanks for looking Mike K