Bryan,
Here's what I have in a repair database from the late 90's, don't know the source...
www.talonix.com/images/RCACTC148.doc
Its in two columns, with the fault in italics, the cure immediately below it. It's an excerpt from a 94 page list.
Hope this helps...I haven't worked a CTC-148 chassis set in a long time.
Cheers,