I note from elsewhere:
seems that a Lot of the SM (as in surface-mount) caps throughout several of the Tek TDS- models suffer from leakers - rendering the thing junk, except to adept and tenacious replacement of dozens of the tiny suckers. (Natch - there's neither schematic nor other service data, nor even expen$ive replacement boards after.. fewer and fewer years; as few as 5 now, I hear.)

Oh and - the alkaline electrolyte eats the surrounding traces; now throw in - thru-holes / multilayer boards.
Imagine scrapping a $10K+ instrument after 4-6 years!

('Course for a mobo, makes sense not even to try.)

Point for you: no SMs in a 454A - yours could go as long as the CRT. Still enough carcasses out there to snag a spare cheap; also, places like [link|http://www.sphere.bc.ca/test/tekparts.html#semi| Sphere] with the knowledgeable Walter Shawlee - even get in new parts like CRTs for Teks.

I won't be messing with any of the New-Tek disposables. (Though given one, I'd likely try hand at shotgunning all the SM caps before trashing.. a guru in Oz claims that is almost guaranteed successful for several TDS models - even in absence of decent info.)



I'd like to see one of my refurbs, turned on (by someone else, natch) just often enough - to make it to 100 years after manufacture. Like some of the 45 yo vac tube models - still. WTF - because its There.