A 3575 tuning oddity that may or may not be cable-system related: This unit occasionally loses its memory and has to go through initial setup, and when it happened again the other day, it developed a glitch with the Minneapolis ABC channels.
First, the environment: we have Charter cable with analog and digital SD service--the Minneapolis stations do not come in OTA. KSTP's digital channels are 5.1 (main channel) and 5.4 (a supplemental channel), and after two full scans, the tuner cannot reliably find 5.1. A timed recording gave a blue screen, and direct-entry tuning would go to 5.4. When I tried stepping up to the 5s from 4.1, it went to 5.4. Next step was 9.1--and then it flipped back to 5.1. But sometimes it does step from 4.1 to 5.1. I don't know enough about what cablecos might do to channel assignments to be sure whether it's Charter fiddling with frequency assignments or some kind of signal-strength fluctuation or what.
And I wonder whether it has to do with another tuning oddity: the three PBS channels are nominally (and according to the station's own information) in the 2.x slots. But a rescan recently resulted in them moving up to 77.x on both the 3575 *and* on our Samsung TV (on which I inadvertantly initiated a channel rescan). 2.x gives blue screen on those devices--but two other Philips DVRs (a 3575 and a 3576), which have not undergone a rescan, still have the 2.x channels. This I take to be the result of Charter moving signals around--but if that's the case, why do the un-rescanned tuners still find the old locations?
I've rummaged through Wajo's excellent hints and procedures and the Minneapolis thread on the HDTV Info forum without finding anything exactly like this. Of course, we're up in St. Cloud, which might be another universe altogether.