Can i line in thru the cd player on an older boombox ?i

I have a GE boombox from the late 80's early 90's in which the cd player stopped working years ago.I have been looking at the instructions on this site for line in thru the cassete player and was curious if it is possible to do the same thing except do it thru the cd lines going to the board .It appears to me that with most of the instructions i have read about the cassete conversion is that the cassete drive motor still runs after this conversion which sucks quit a bit of juice,which may not seem like a big deal to most but i go on canoe trips for 3-5 days at a time when no power is available other than the batteries I bring on the trip so it would be nice to line in and not have any motors that are not necessary running. If not i will use one of the great tutorials for the cassete way of doing it. Thanks dave