TAS 485 schematic

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Looking for one, &| a service manual. Note that this is not the Tektronix 485, but the Tektronix TAS 485. I already made that mistake.
I did find a service manual for a TAS 465 on the TekWiki, perhaps it is close enough to be useful? (100 MHz 2 channel vs my 200 MHz 4 channel, otherwise the grainy monochrome scan seems like a visual match)

On a side note, I have instrumentation for only a rudimentary calibration, so I greatly fear losing the current cal data, if it's even there still. Are there any gotchas that I might be able to avoid? Symptoms are failure to boot, no activity on the screen or in response to stimulus—including tube brightness, etc. All LEDs are lit solid. When I switch it off, there is a flash of the beam on the centerish of the tube, similar to the turn-off of an old TV, so I'm hopeful the HV is intact.

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The TekWiki has a few resources, an instruction manual (PDF) and service manual (PDF) that I guess are close enough to be useful. I found a reference to a TAS 485 service manual here that covers serial numbers prior to B020099, after that they are repaired by module replacement. Sadly, the only reference Google has found for that part number is an old auction on eBay.es.