I have a S2 Tivo and a Motorola DCT2000 series stb. My Tivo changes channels on Charter Comm's set top box using a serial connector cable. Everything has worked well for years.
A new problem started a few weeks ago. When my tivo tries to change to certain channels, the channel would keep changing either up or down until it hits a station it could lock onto. I can see the Tivo is successful in changing to the requested channel, but it seems the Tivo doesn't get a signal from the set top box in time, and so automatically changes to next nearest station, and so on, until it finds one that it senses is there. If I change the channel with the stb remote, channels change normally, though there is a noticeable lag.
I tried rebooting both the stb and the tivo, and reducing the time the guide banner in the set top box shows to 2 secs. These attempted fixes didn't help.
FInally I called Charter, asked for a replacement box. The repairman came out today, tried putting a MTR700 Motorola TA box onto the Tivo S2 until he found out that it wasn't compatible with it. He tried changing out the stb for another Motorola DCT2000 series box. This didn't fix the problem. He says they have recently started converting to Switched Digital Video - only some channels have been converted. Apparently, he, explains, it takes longer to change to the SDV channels, as they have to request a video feed from the office, in a similar way to OnDemand channels.
Are other Tivo S2 owners (who channel change using a serial connector) running into a problem SDV causing the Tivo to cycle through channels? Has anyone found a workaround for this, other than an ir blaster? For example, is there a way to disable the default behavior where Tivo cycles through channels until it picks up a signal? Right now I am using ir blaster which works, but I would rather use the serial connector if possible.
Thanks for all your insights,