MMR1 intermittent failure
After tuning ILS 1 & 2, setting up for approach in marginal weather, noticed that ILS 1 tuning was intermittent (indications switched between freq/course to IDENT/course)...and ILS 2 was rock solid IDENT. This situation prevented a dual autopilot autoland and also NO AIII capability...only the ILS 2 was available for an instrument approach. Next day, after talking to Maintenance regarding the writeup...come to find out that a failure of MMR 1 had occurred...according to them, this never happens! There is no comparator between these and you wouldn't know you suffered this problem until on final and no Cat2/Cat3 capability.