[ChrisW6ATV]

I haven't had a chance to get on AK for a while, and I am fascinated by the recent information.

Since you have tried several tapes, and several machines, and not had a lot of success (at least with the video part), it might be best to kind of start over with a methodical process, with the playing and transferring of your family tape(s) as the last step.

-Read plenty about the restoring of old electronics, and VCRs specifically if you can find details, here on AK or elsewhere as well.
-All of this equipment is 35 years old, and unused or not, many of the electrolytic capacitors ("caps") have probably gone bad. (The TV picture has bad vertical linearity, for example, and that is probably just one or two bad caps.) Buy or build an ESR meter; they are pretty simple, and they are exactly what you need to (relatively) quickly test every electrolytic cap.
-Pick one machine, and try everything on it (cap checking, lubrication, audio/video in and out connections, etc.), and make notes of everything you do.
-Besides the A/V outputs, connect audio and video inputs on a machine and try recording: Pick one blank tape if you have one (NOT one of your family tapes, and not one of the tapes with prerecorded shows), and do all of your testing with that one tape. Connect the outputs of another A/V device (a regular VCR tuned to a TV station will work until June, or use one of the cheap new digital TV converter boxes). Set the Cartrivision unit into Record mode for about ten minutes, then rewind the tape and play it and see what you get. Most video recorders play their own recordings better than tapes from any other machine; once the machine can record and play its own video, then move on to playing existing tapes. (The reason for this issue is tape drive/head alignment, tape tension, etc. If you have ever had a floppy disk drive that would not read other disks but would write and read its own disks fine, it is the same concept.) If you get anything at all on this tape that you record (sound, video, color, or all), keep using it for more tests (and more recordings) as you go along. Later, move on to possible alignment of the machine to get other tapes playing better. Recorded tapes themselves that have sat for 30+ years can and will deteriorate, stretch, or whatever, so you may never get nearly the quality out of any of the old material compared to that of new recordings, but working this way will eliminate recorded-tape quality issues from problems with the machine itself.
-If you don't already have one, get an oscilloscope. It will make looking at/for the audio and video signals much easier as you work on the equipment.
-Someone somewhere has to have service information on these units still. Besides a plain Google search, try the "groups" search option in Google with the word Cartrivision (and misspelled variants as well). Send messages to any e-mail addresses you find, and to all the owners of the Web sites you find about Cartrivision equipment.

Your existing skills should make all of this easier than for many collectors. Keep us posted on further progress.